Anti-ifnar1 antibodies for treating autoimmune diseases

ABSTRACT

Provided are antibodies or fragments thereof having binding specificity to the human interferon alpha and beta receptor subunit 1 (IFNAR1) protein. In various examples, the antibodies or fragments thereof include a VH and VL CDRs as disclosed herein, or variants thereof. Methods of using the antibodies or fragments thereof for treating autoimmune diseases and disorders are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 16/963,128, filed Jul. 17, 2020, now U.S. Pat. No. 11,059,897, which is the U.S. National Stage Application under 35 U.S.C. 371 of International Application No. PCT/CN2019/106412, filed Sep. 18, 2019, which claims priority to International Application PCT/CN2018/106157, filed Sep. 18, 2018. The contents of each of the aforementioned are hereby incorporated by reference in their entirety into the present disclosure.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has been filed electronically in ASCII format and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Jul. 11, 2021, is named 271415US2_SL.txt and is 102,221 bytes in size.

BACKGROUND

Systemic lupus erythematosus (SLE), also known simply as lupus, is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms.

The cause of SLE is not clear. The mechanism involves an immune response by autoantibodies against a person's own tissues. These are most commonly anti-nuclear antibodies and they result in inflammation. There is no cure for SLE. Treatments may include NSAIDs, corticosteroids, immunosuppressants, hydroxychloroquine, and methotrexate. SLE significantly increases the risk of cardiovascular disease with this being the most common cause of death.

Type I IFNs, particularly the IFN-αs and IFN-0, have received attention for their roles in the pathogenesis of SLE and other autoimmune and inflammatory syndromes. By signaling through a common receptor (IFNAR), these pleiotropic cytokines affect almost every aspect of innate and adaptive immune responses, including upregulation of MHC and costimulatory molecules, and production of B cell survival factors (BAFF, April) by antigen-presenting cells, culminating in the engagement and expansion of autoreactive T and B cells. Of particular relevance to lupus pathogenesis is the induction of type I IFNs under sterile conditions through the engagement of endosomal Toll-like receptors (TLRs) by self-nucleic acids. There has been extensive interest in creating treatments based on blocking reagents against either the multiple IFN-αs and the single IFN-β, or their common receptor.

SUMMARY

The present disclosure provides antibodies or fragments thereof having binding specificity to the human interferon alpha and beta receptor subunit 1 (IFNAR1) protein, as well as bispecific antibodies having specificity to IFNAR1 and another antigen such as BAFF. These antibodies and fragments are useful in the treatment of autoimmune diseases such as systemic lupus erythematosus.

One embodiment of the present disclosure provides an antibody or fragment thereof having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein, wherein the antibody or fragment thereof comprises a heavy chain variable region comprising heavy chain complementarity determining regions HCDR1, HCDR2, and HCDR3, and a light chain variable region comprising light chain complementarity determining regions LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 are selected from the group consisting of: (a) HCDR1: DYYMH (SEQ ID NO: 77), HCDR2: RIDPEDGETKYAPKFQG (SEQ ID NO: 78) or RIDPEDAETKYAPKFQG (SEQ ID NO:79), HCDR3: GGNFYVMDY (SEQ ID NO: 80), LCDR1: KASQNVGTNVV (SEQ ID NO: 81), LCDR2: SASYRVS (SEQ ID NO: 82), and LCDR3: QQKNNYPYT (SEQ ID NO: 83); and (b) HCDR1: DYYIH (SEQ ID NO: 92), HCDR2: RIDPEDGETKYAPKFQG (SEQ ID NO: 93) or RIDPEDAETKYAPKFQG (SEQ ID NO:94), HCDR3: YHGYWALDY (SEQ ID NO: 95), LCDR1: KTSQNVGTNVA (SEQ ID NO: 96), LCDR2: STSYRYS (SEQ ID NO: 97), and LCDR3: HQYFSYPYT (SEQ ID NO: 98).

In some embodiments, the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 are HCDR1: DYYMH (SEQ ID NO: 77), HCDR2: RIDPEDAETKYAPKFQG (SEQ ID NO:79), HCDR3: GGNFYVMDY (SEQ ID NO: 80), LCDR1: KASQNVGTNVV (SEQ ID NO: 81), LCDR2: SASYRVS (SEQ ID NO: 82), and LCDR3: QQKNNYPYT (SEQ ID NO: 83).

In some embodiments, the antibody or fragment thereof comprises a heavy chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 7, and 84-87 (e.g., SEQ ID NO:85), or a peptide having at least 90% sequence identity to an amino acid sequence selected from the group consisting of SEQ ID NO: 7, and 84-87 (e.g., SEQ ID NO:85). In some embodiments, the antibody or fragment thereof comprises a light chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 8, and 88-91 (e.g., SEQ ID NO:88), or a peptide having at least 90% sequence identity to an amino acid sequence selected from the group consisting of SEQ ID NO: 8, and 88-91 (e.g., SEQ ID NO:88). The heavy chain variable region and the light chain variable, as recited here, include the CDR regions as recited above.

In some embodiments, the antibody or fragment thereof comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 85, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 88.

In some embodiments, the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 are HCDR1: DYYIH (SEQ ID NO: 92), HCDR2: RIDPEDAETKYAPKFQG (SEQ ID NO:94), HCDR3: YHGYWALDY (SEQ ID NO: 95), LCDR1: KTSQNVGTNVA (SEQ ID NO: 96), LCDR2: STSYRYS (SEQ ID NO: 97), and LCDR3: HQYFSYPYT (SEQ ID NO: 98).

In some embodiments, the antibody or fragment thereof comprises a heavy chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 73, and 99-102 (e.g., SEQ ID NO:100), or a peptide having at least 90% sequence identity to an amino acid sequence selected from the group consisting of SEQ ID NO: 73, and 99-102 (e.g., SEQ ID NO:100).

In some embodiments, the antibody or fragment thereof comprises a light chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 74, and 103-106 (e.g., SEQ ID NO:105), or a peptide having at least 90% sequence identity to an amino acid sequence selected from the group consisting of SEQ ID NO: 74, and 103-106 (e.g., SEQ ID NO:105).

In some embodiments, the antibody or fragment thereof comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 100, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 105.

In another embodiments, provided is an antibody or fragment thereof having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein, wherein the antibody or fragment thereof can bind to one or more amino acid residues selected from the group consisting of H273, L274, Y275, K276, and K278 of the IFNAR1 protein.

In some embodiments, the antibody or fragment thereof of claim can bind to at least two of the amino acid residues selected from the group, such as K276, and K278. In some embodiments, the antibody or fragment thereof of claim can bind to at least three of the amino acid residues selected from the group, such as H273, K276, and K278; L274, K276, and K278; Y275, K276, and K278; or Y275, K276, and K278. In some embodiments, the antibody or fragment thereof of claim can bind to at least four, five or all of the amino acid residues selected from the group.

Also provided, in one embodiment, is a bifunctional molecule, comprising a first antigen-binding portion having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein and a second portion having specificity to a second protein, wherein the first antigen-binding portion comprises an antibody fragment of the present disclosure.

In some embodiments, the second portion comprises peptide edratide (hCDR1) or TACI-Ig. In some embodiments, the second portion is an antigen-binding fragment having specificity to a protein selected from the group consisting of BAFF, CD20, CD22, CTLA4, IL6, CXCL13 and C5. In some embodiments, the second portion is an antigen-binding fragment having specificity to a human B-cell-activating factor (BAFF) protein.

In some embodiments, the bifunctional molecule has a format comprising a full antibody fused to two single chain fragments (scFv) or to two Fab fragments (as illustrated as Format 1 herein). In some embodiments, the second portion comprises an antigen-binding fragment of Belimumab.

Uses and methods of the presently disclosed antibodies and fragments are also provided. For instance, the presently disclosed antibodies and fragments can be used for suppressing an immune response or treating an autoimmune disease or disorder in a patient in need thereof.

In some embodiments, the autoimmune disease or disorder is selected from the group consisting of type 1 diabetes, rheumatoid arthritis (RA), psoriasis/psoriatic arthritis, multiple sclerosis, systemic lupus erythematosus (lupus), inflammatory bowel disease, Addison's disease, Graves' disease, Sjögren's syndrome, Hashimoto's thyroiditis, myasthenia gravis, vasculitis, pernicious anemia, and celiac disease. In some embodiments, the autoimmune disease or disorder is systemic lupus erythematosus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-B show that the 8G11H and 485G10H antibodies efficiently blocked IFNαc2b-induced reporter gene expression, with potency comparable to that of the corresponding chimeric antibodies.

FIG. 2A-B show that 8G11H and 485G10H antibodies dose-dependently reversed IFNαc2b-mediated inhibition of Daudi cell proliferation.

FIG. 3 shows that 8G11H and 485G10H dose-dependently inhibited recombinant IFNαc2b-induced secretion of IP-10 by normal PBMC culture.

FIG. 4 shows that the 8G11H and 485G10H antibodies efficiently inhibited the in vitro differentiation of dendritic cells as demonstrated by significant reduction of differentiated cell surface markers CD38 and CD86 expression.

FIG. 5 shows that the 8G11H and 485G10H antibodies efficiently inhibited the in vitro differentiation of dendritic cells, which resulted in impaired responses in differentiated cell-mediated MLR as demonstrated by decreased production of IFN-γ by CD4⁺ T cells.

FIG. 6 shows that humanized monoclonal antibodies 8G11H and 485G10H significantly inhibited the SLE plasma mediated dendritic cell development in in vitro system.

FIG. 7 depicts a schematic of designed four formats for the anti-IFNAR/BAFF bispecific antibody (Bi-BFINR).

FIG. 8 shows that the bispecific antibody exhibited similar activity with 8G11 antibody in binding to IFNAR-1 and comparable activity to Belimumab in binding to BAFF.

FIG. 9A-B show that Bi-BFINF antibody had comparable activity to chimeric 8G11 in blocking IFNα2b signaling (A); Bi-BFINF antibody exhibited better activity in blockade of BAFF-induced B cell proliferation (B).

FIG. 10A shows time-concentration profiles of 485G10H1L3 in 2 cynomolgus monkeys.

FIG. 10B shows time-concentration profiles of 8G11H2L1 in 2 cynomolgus monkeys.

FIG. 11A shows CD11C, CD38, CD86, MHC Class I, MHC Class II and IFN-alpha R1 expression by FACs after dosing at 24 h, 48 h and 72 h.

FIG. 11B shows the serum level of monkey neopterin, beta-2-microglobulin and CRP at 24 h, 48 h and 72 h after dosing.

FIG. 11C shows the expression levels of type I IFN-induced gene signatures in monkey PBMCs at 24 h, 48 h and 72 h after dosing.

DETAILED DESCRIPTION Definitions

It is to be noted that the term “a” or “an” entity refers to one or more of that entity; for example, “an antibody,” is understood to represent one or more antibodies. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein.

As used herein, an “antibody” or “antigen-binding polypeptide” refers to a polypeptide or a polypeptide complex that specifically recognizes and binds to an antigen. An antibody can be a whole antibody and any antigen binding fragment or a single chain thereof. Thus the term “antibody” includes any protein or peptide containing molecule that comprises at least a portion of an immunoglobulin molecule having biological activity of binding to the antigen. Examples of such include, but are not limited to a complementarity determining region (CDR) of a heavy or light chain or a ligand binding portion thereof, a heavy chain or light chain variable region, a heavy chain or light chain constant region, a framework (FR) region, or any portion thereof, or at least one portion of a binding protein.

The terms “antibody fragment” or “antigen-binding fragment”, as used herein, is a portion of an antibody such as F(ab′)₂, F(ab)₂, Fab′, Fab, Fv, scFv and the like. Regardless of structure, an antibody fragment binds with the same antigen that is recognized by the intact antibody. The term “antibody fragment” includes aptamers, spiegelmers, and diabodies. The term “antibody fragment” also includes any synthetic or genetically engineered protein that acts like an antibody by binding to a specific antigen to form a complex.

A “single-chain variable fragment” or “scFv” refers to a fusion protein of the variable regions of the heavy (V_(H)) and light chains (V_(L)) of immunoglobulins. In some aspects, the regions are connected with a short linker peptide of ten to about 25 amino acids. The linker can be rich in glycine for flexibility, as well as serine or threonine for solubility, and can either connect the N-terminus of the V_(H) with the C-terminus of the V_(L), or vice versa. This protein retains the specificity of the original immunoglobulin, despite removal of the constant regions and the introduction of the linker. ScFv molecules are known in the art and are described, e.g., in U.S. Pat. No. 5,892,019.

The term antibody encompasses various broad classes of polypeptides that can be distinguished biochemically. Those skilled in the art will appreciate that heavy chains are classified as gamma, mu, alpha, delta, or epsilon (γ, μ, α, δ, ϵ) with some subclasses among them (e.g., γ1-γ4). It is the nature of this chain that determines the “class” of the antibody as IgG, IgM, IgA IgG, or IgE, respectively. The immunoglobulin subclasses (isotypes) e.g., IgG₁, IgG₂, IgG₃, IgG₄, IgG₅, etc. are well characterized and are known to confer functional specialization. Modified versions of each of these classes and isotypes are readily discernable to the skilled artisan in view of the instant disclosure and, accordingly, are within the scope of the instant disclosure. All immunoglobulin classes are clearly within the scope of the present disclosure, the following discussion will generally be directed to the IgG class of immunoglobulin molecules. With regard to IgG, a standard immunoglobulin molecule comprises two identical light chain polypeptides of molecular weight approximately 23,000 Daltons, and two identical heavy chain polypeptides of molecular weight 53,000-70,000. The four chains are typically joined by disulfide bonds in a “Y” configuration wherein the light chains bracket the heavy chains starting at the mouth of the “Y” and continuing through the variable region.

Antibodies, antigen-binding polypeptides, variants, or derivatives thereof of the disclosure include, but are not limited to, polyclonal, monoclonal, multispecific, human, humanized, primatized, or chimeric antibodies, single chain antibodies, epitope-binding fragments, e.g., Fab, Fab′ and F(ab′)₂, Fd, Fvs, single-chain Fvs (scFv), single-chain antibodies, disulfide-linked Fvs (sdFv), fragments comprising either a VK or VH domain, fragments produced by a Fab expression library, and anti-idiotypic (anti-Id) antibodies (including, e.g., anti-Id antibodies to LIGHT antibodies disclosed herein) Immunoglobulin or antibody molecules of the disclosure can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) or subclass of immunoglobulin molecule.

Light chains are classified as either kappa or lambda (K, λ). Each heavy chain class may be bound with either a kappa or lambda light chain. In general, the light and heavy chains are covalently bonded to each other, and the “tail” portions of the two heavy chains are bonded to each other by covalent disulfide linkages or non-covalent linkages when the immunoglobulins are generated either by hybridomas, B cells or genetically engineered host cells. In the heavy chain, the amino acid sequences run from an N-terminus at the forked ends of the Y configuration to the C-terminus at the bottom of each chain.

Both the light and heavy chains are divided into regions of structural and functional homology. The terms “constant” and “variable” are used functionally. In this regard, it will be appreciated that the variable domains of both the light (VK) and heavy (VH) chain portions determine antigen recognition and specificity. Conversely, the constant domains of the light chain (CK) and the heavy chain (CH1, CH2 or CH3) confer important biological properties such as secretion, transplacental mobility, Fc receptor binding, complement binding, and the like. By convention the numbering of the constant region domains increases as they become more distal from the antigen-binding site or amino-terminus of the antibody. The N-terminal portion is a variable region and at the C-terminal portion is a constant region; the CH3 and CK domains actually comprise the carboxy-terminus of the heavy and light chain, respectively.

As indicated above, the variable region allows the antibody to selectively recognize and specifically bind epitopes on antigens. That is, the VK domain and VH domain, or subset of the complementarity determining regions (CDRs), of an antibody combine to form the variable region that defines a three dimensional antigen-binding site. This quaternary antibody structure forms the antigen-binding site present at the end of each arm of the Y. More specifically, the antigen-binding site is defined by three CDRs on each of the VH and VK chains (i.e. CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2 and CDR-L3). In some instances, e.g., certain immunoglobulin molecules derived from camelid species or engineered based on camelid immunoglobulins, a complete immunoglobulin molecule may consist of heavy chains only, with no light chains. See, e.g., Hamers-Casterman et al., Nature 363:446-448 (1993).

In naturally occurring antibodies, the six “complementarity determining regions” or “CDRs” present in each antigen-binding domain are short, non-contiguous sequences of amino acids that are specifically positioned to form the antigen-binding domain as the antibody assumes its three dimensional configuration in an aqueous environment. The remainder of the amino acids in the antigen-binding domains, referred to as “framework” regions, show less inter-molecular variability. The framework regions largely adopt a β-sheet conformation and the CDRs form loops which connect, and in some cases form part of, the β-sheet structure. Thus, framework regions act to form a scaffold that provides for positioning the CDRs in correct orientation by inter-chain, non-covalent interactions. The antigen-binding domain formed by the positioned CDRs defines a surface complementary to the epitope on the immunoreactive antigen. This complementary surface promotes the non-covalent binding of the antibody to its cognate epitope. The amino acids comprising the CDRs and the framework regions, respectively, can be readily identified for any given heavy or light chain variable region by one of ordinary skill in the art, since they have been precisely defined (see “Sequences of Proteins of Immunological Interest,” Kabat, E., et al., U.S. Department of Health and Human Services, (1983); and Chothia and Lesk, J. Mol. Biol., 196:901-917 (1987)).

In the case where there are two or more definitions of a term which is used and/or accepted within the art, the definition of the term as used herein is intended to include all such meanings unless explicitly stated to the contrary. A specific example is the use of the term “complementarity determining region” (“CDR”) to describe the non-contiguous antigen combining sites found within the variable region of both heavy and light chain polypeptides. This particular region has been described by Kabat et al., U.S. Dept. of Health and Human Services, “Sequences of Proteins of Immunological Interest” (1983) and by Chothia et al., J. Mol. Biol. 196:901-917 (1987), which are incorporated herein by reference in their entireties. The CDR definitions according to Kabat and Chothia include overlapping or subsets of amino acid residues when compared against each other. Nevertheless, application of either definition to refer to a CDR of an antibody or variants thereof is intended to be within the scope of the term as defined and used herein. The appropriate amino acid residues which encompass the CDRs as defined by each of the above cited references are set forth in the table below as a comparison. The exact residue numbers which encompass a particular CDR will vary depending on the sequence and size of the CDR. Those skilled in the art can routinely determine which residues comprise a particular CDR given the variable region amino acid sequence of the antibody.

Antibodies disclosed herein may be from any animal origin including birds and mammals Preferably, the antibodies are human, murine, donkey, rabbit, goat, guinea pig, camel, llama, horse, or chicken antibodies. In another embodiment, the variable region may be condricthoid in origin (e.g., from sharks).

As used herein, the term “heavy chain constant region” includes amino acid sequences derived from an immunoglobulin heavy chain. A polypeptide comprising a heavy chain constant region comprises at least one of: a CH1 domain, a hinge (e.g., upper, middle, and/or lower hinge region) domain, a CH2 domain, a CH3 domain, or a variant or fragment thereof. For example, an antigen-binding polypeptide for use in the disclosure may comprise a polypeptide chain comprising a CH1 domain; a polypeptide chain comprising a CH1 domain, at least a portion of a hinge domain, and a CH2 domain; a polypeptide chain comprising a CH1 domain and a CH3 domain; a polypeptide chain comprising a CH1 domain, at least a portion of a hinge domain, and a CH3 domain, or a polypeptide chain comprising a CH1 domain, at least a portion of a hinge domain, a CH2 domain, and a CH3 domain. In another embodiment, a polypeptide of the disclosure comprises a polypeptide chain comprising a CH3 domain. Further, an antibody for use in the disclosure may lack at least a portion of a CH2 domain (e.g., all or part of a CH2 domain). As set forth above, it will be understood by one of ordinary skill in the art that the heavy chain constant region may be modified such that they vary in amino acid sequence from the naturally occurring immunoglobulin molecule.

The heavy chain constant region of an antibody disclosed herein may be derived from different immunoglobulin molecules. For example, a heavy chain constant region of a polypeptide may comprise a CH1 domain derived from an IgG1 molecule and a hinge region derived from an IgG₃ molecule. In another example, a heavy chain constant region can comprise a hinge region derived, in part, from an IgG₁ molecule and, in part, from an IgG₃ molecule. In another example, a heavy chain portion can comprise a chimeric hinge derived, in part, from an IgG₁ molecule and, in part, from an IgG₄ molecule.

As used herein, the term “light chain constant region” includes amino acid sequences derived from antibody light chain. Preferably, the light chain constant region comprises at least one of a constant kappa domain or constant lambda domain.

A “light chain-heavy chain pair” refers to the collection of a light chain and heavy chain that can form a dimer through a disulfide bond between the CL domain of the light chain and the CH1 domain of the heavy chain.

As previously indicated, the subunit structures and three dimensional configuration of the constant regions of the various immunoglobulin classes are well known. As used herein, the term “VH domain” includes the amino terminal variable domain of an immunoglobulin heavy chain and the term “CH1 domain” includes the first (most amino terminal) constant region domain of an immunoglobulin heavy chain. The CH1 domain is adjacent to the VH domain and is amino terminal to the hinge region of an immunoglobulin heavy chain molecule.

As used herein the term “CH2 domain” includes the portion of a heavy chain molecule that extends, e.g., from about residue 244 to residue 360 of an antibody using conventional numbering schemes (residues 244 to 360, Kabat numbering system; and residues 231-340, EU numbering system; see Kabat et al., U.S. Dept. of Health and Human Services, “Sequences of Proteins of Immunological Interest” (1983). The CH2 domain is unique in that it is not closely paired with another domain. Rather, two N-linked branched carbohydrate chains are interposed between the two CH2 domains of an intact native IgG molecule. It is also well documented that the CH3 domain extends from the CH2 domain to the C-terminal of the IgG molecule and comprises approximately 108 residues.

As used herein, the term “hinge region” includes the portion of a heavy chain molecule that joins the CH1 domain to the CH2 domain. This hinge region comprises approximately 25 residues and is flexible, thus allowing the two N-terminal antigen-binding regions to move independently. Hinge regions can be subdivided into three distinct domains: upper, middle, and lower hinge domains (Roux et al., J. Immunol 161:4083 (1998)).

As used herein the term “disulfide bond” includes the covalent bond formed between two sulfur atoms. The amino acid cysteine comprises a thiol group that can form a disulfide bond or bridge with a second thiol group. In most naturally occurring IgG molecules, the CH1 and CK regions are linked by a disulfide bond and the two heavy chains are linked by two disulfide bonds at positions corresponding to 239 and 242 using the Kabat numbering system (position 226 or 229, EU numbering system).

As used herein, the term “chimeric antibody” will be held to mean any antibody wherein the immunoreactive region or site is obtained or derived from a first species and the constant region (which may be intact, partial or modified in accordance with the instant disclosure) is obtained from a second species. In certain embodiments the target binding region or site will be from a non-human source (e.g. mouse or primate) and the constant region is human.

By “specifically binds” or “has specificity to,” it is generally meant that an antibody binds to an epitope via its antigen-binding domain, and that the binding entails some complementarity between the antigen-binding domain and the epitope. According to this definition, an antibody is said to “specifically bind” to an epitope when it binds to that epitope, via its antigen-binding domain more readily than it would bind to a random, unrelated epitope. The term “specificity” is used herein to qualify the relative affinity by which a certain antibody binds to a certain epitope. For example, antibody “A” may be deemed to have a higher specificity for a given epitope than antibody “B,” or antibody “A” may be said to bind to epitope “C” with a higher specificity than it has for related epitope “D.”

As used herein, the terms “treat” or “treatment” refer to both therapeutic treatment and prophylactic or preventative measures, wherein the object is to prevent or slow down (lessen) an undesired physiological change or disorder, such as the progression of cancer. Beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, diminishment of extent of disease, stabilized (i.e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. “Treatment” can also mean prolonging survival as compared to expected survival if not receiving treatment. Those in need of treatment include those already with the condition or disorder as well as those prone to have the condition or disorder or those in which the condition or disorder is to be prevented.

By “subject” or “individual” or “animal” or “patient” or “mammal,” is meant any subject, particularly a mammalian subject, for whom diagnosis, prognosis, or therapy is desired. Mammalian subjects include humans, domestic animals, farm animals, and zoo, sport, or pet animals such as dogs, cats, guinea pigs, rabbits, rats, mice, horses, cattle, cows, and so on.

As used herein, phrases such as “to a patient in need of treatment” or “a subject in need of treatment” includes subjects, such as mammalian subjects, that would benefit from administration of an antibody or composition of the present disclosure used, e.g., for detection, for a diagnostic procedure and/or for treatment.

Anti-IFNAR1 Antibodies

The present disclosure provides antibodies, including bispecific antibodies and fragments, that have binding specificity to the human interferon alpha and beta receptor subunit 1 (IFNAR1) protein. As demonstrated in the experimental examples, numerous murine anti-human IFNAR1 antibodies were obtained, having high binding affinity to the human IFNAR1 protein. Two of the murine antibody clones, 8G11 and 485G10, were selected for further humanization and characterization. The humanized antibodies dose-dependently reversed IFNαc2b-mediated inhibition of Daudi cell proliferation, IFNαc2b-induced anti-viral function as well as efficiently inhibited the cell signal elicited by multiple type I IFNs at pM levels. The IFNs included IFNα 1, IFNα 2a, IFNα 4, IFNα 5, IFNα 6, IFNα 7, IFNα 8, IFNα 10, IFNα 14, IFNα 16, IFNα 17, and IFNα 21.

Additional functional studies showed that these antibodies efficiently inhibited IFNα2b-induced secretion of IP-10 by human PBMCs and inhibited IFNα-dependent or SLE plasma-mediated dendritic cell development as demonstrated by reduced cell surface markers CD38 and CD86 expression, and decreased production of IFN-γ by CD4+ T cells in MLR system.

Various formats of anti-IFNAR1/anti-BAFF bispecific antibodies were also prepared and tested for their binding capabilities and biological functions. These bispecific antibodies exhibited comparable binding activity to monospecific 8G11 in blocking IFNα2b signaling, and even better activity in blockade of BAFF-induced B cell proliferation.

In accordance with one embodiment of the present disclosure, provided are antibodies and fragments thereof that include the heavy chain and light chain variable domains with the CDR regions of the antibodies prepared in the experimental examples. The CDRs are summarized in Table A below.

TABLE A CDR Sequences Antibody CDR Sequences (CDR1, CDR2, chain CDR3 in order, for VH or VL) SEQ ID NO: 4A6-VH DYYMH 77 RIDPDDGETKYAPKFQG 107 GGNYYVMDN 108 4A6-VL KASQNVGTNVA 109 TASYRYS 110 QQYFSYPHT 111 4B12-VH DSYMH 112 RIDPEDGETNYAPKFQG 113 RVSSLYAMDY 114 4B12-VL KASQNVGTNVA 109 LASYRYS 115 QQYNNYPWT 116 4D8-VH DYYMH 77 RIDPEDAETKYAPKFQG 79 GGNFYVMDY 80 4D8-VL KASQNVGTNVV 81 SASYRYS 117 QQKNSYPYT 118 8G11-VH DYYMH 77 RIDPEDGETKYAPKFQG 78 GGNFYVMDY 80 8G11-VL KASQNVGTNVV 81 SASYRVS 82 QQKNNYPYT 83 12G11-VH DYYMH 77 RIDPEDGETKYAPKFQG 78 GGNYYAMDY 119 12G11-VL KASQNVGTNVA 109 SASYRYS 117 QQHNSYTYK 120 17F9-VH DYYIH 92 RIDPEDGETKYAPKFQD 121 YDGYYGFDY 122 17F9-VL KASQNVGTNVA 109 STSYRYS 97 HQYNNYPYT 123 18B6-VH DYYMC 124 RIDPEDGETKYAPKFQG 78 GGNYYAMDY 119 18B6-VL KASQNVGTNVA 109 SATYRYS 125 QQHNSYSYT 126 18C1-VH DYYMH 77 RIDPEDGETKYAPKFQG 78 LGNWVFDY 127 18C1-VL KASQNVGTNVD 128 SASYRYS 117 QQYNTYT 129 19B6-VH DYYMH 77 RIDPEDGETKYAPKFQV 130 GGNFYYFDY 131 19B6-VL KASQNVGTNVA 109 SASYRYS 117 QQCINYPYT 132 20B3-VH DYYIH 92 RIDPEDGETKYAPTFQG 133 YNGYSGFDY 134 20B3-VL KASQNVGTNVV 81 SASYRYS 117 QQYNRYPFT 135 20E10-VH DYYIH 92 RIDPEDGETKYAPKFQD 121 YDGYYGFDY 122 20E10-VL KASQNVGTNVA 109 STSYRYS 97 HQYNNYPYT 123 20E12-VH DYYMH 77 RIDPEDGETKYVPKFQG 136 GGSYYVMDY 137 20E12-VL KASQNVGTSVA 138 SASYRYS 117 QQDNSYPHT 139 21D6-VH DYYMH 77 RIDPEDGETKYAPKFQG 78 LHWSLDS 140 21D6-VL KASQNVGTAVA 141 STANRDT 142 QQYSSYPYT 143 24F6-VH DYYIH 92 RVDPEDGETKYVPKFLD 144 GGNYYAMDY 119 24F6-VL KASQNVGTNVA 109 LASYRYS 115 QQCNNYRLT 145 29E12-VH DYYIH 92 RIDPEDGETKYAPKFQD 121 YDGYYGFDY 122 29E12-VL KASQNVGTNVA 109 STSYRYS 97 HQYNNYPYT 123 30B5-VH DSYIH 146 RIDPEDGETKYAPKFQG 78 WLADYSAMDN 147 30B5-VL KASEDIYNRLA 148 GATSLET 149 QQYWNTLYT 150 30C8-VH DSYMH 112 RIDPEDGETKYAPKFQG 78 RGSSLYAVDY 151 30C8-VL KASQNVGTSVA 138 LASYRHR 152 QQFNIYPWT 153 34H8-VH DYYLH 154 RIDPEDGETKYAPKFQG 78 GGNYDVMDY 155 34H8-VL KASQNVGTYVV 156 SASYRYS 117 QQKNTYPFT 157 36E3-VH DSYMH 112 RIDPEDGETKYAPKFQG 78 RGSSLYAVDY 151 36E3-VL KASQNVGTSVA 138 LASYRHR 152 QQFNIYPWT 153 39F5-VH DYYIH 92 RIDPEDGETKYAPKFQV 130 GGNFYYFDY 131 39F5-VL KASQNVGTNVA 109 SASYRYS 117 QQCINYPYT 132 41F1-VH DYYMH 77 RIDPEDGETKYVPKFQG 136 GGNYYVMDY 158 41F1-VL KASQNVGTYVA 159 SASYRYN 160 QQYNNYPLT 161 46A10-VH DYYMH 77 RIDPEDGETKYAPKFQV 130 GGNFYYFDF 162 46A10-VL KASQNVGTNVA 109 SASYRYS 117 QQCINYPYT 132 47C6-VH DYYIH 92 RIDPEDGETKYAPKFQG 78 GGNFYYFDY 131 47C6-VL KASQNVGTNVA 109 SASYRYS 117 QQCNSYSYT 163 47F5-VH DYYMH 77 RIDPEDGETKYVPKFQG 136 GGSYYVMDY 137 47F5-VL KASQNVGTSVA 138 SASYRYS 117 QQDNSYPHT 139 104A3-VH DYYIH 92 RIDPEDGETKYAPKFQG 78 YDGYYCFDY 164 104A3-VL KASQNVGTNVA 109 STSYRYS 97 QQYNNYPYT 165 106A7-VH DYYMH 77 RIDPEDGETKYAPKFQG 78 DWGHSFDY 166 106A7-VL KASQNVGTTVA 167 SASYRYS 117 QQYNSYT 168 107E12-VH DYYIH 92 RIDPEDGETKYAPKFQD 121 EGSFTGWFPY 169 107E12-VL KARQSVGTYVA 170 STSYRYN 171 QQYHSYPYT 172 124D12-VH DYYIH 92 RIDPEDGETKYAPKFQG 78 YDGYYCFDY 164 124D12-VL KASQNVGTNVA 109 STSYRYS 97 QQYNNYPYT 165 260H8-VH SDYWN 173 YISYSGSIYYNPSLKS 174 SGGMYYFDY 175 260H8-VL RASGNIHNYLA 176 NAKTLED 177 QHFWSIPPT 178 268E9-VH SDYWN 173 YISYSGSIYYNPSLKS 174 SGGMYYFDY 175 268E9-VL RASGNIHNYLA 176 NAKTLED 177 QHFWSIPPT 178 269A7-VH SDYWN 173 YISYSGTIYYNPSLKS 179 SGGMYYFDY 175 269A7-VL RASGNIHNYLA 176 NAKTLED 177 QHFWSIPPT 178 293H10-VH SDYWN 173 YISYSGNTDYNPSLKS 180 SEGMYFFDY 181 293H10-VL RASGNIHNYLA 176 NAKTLAD 182 QHFWSTPPT 183 370E5-VH DYYIH 92 RIDPEDGETKYAPKFQG 78 FGGLTAMDY 184 370E5-VL KASQNVGTNVA 109 ATSYRYS 185 QQYNNYPYT 165 392D6-VH DYYVH 186 RIDPEDGETKYAPKFQG 78 FGGLDAMDY 187 392D6-VL KASQNVGTNVA 109 STSYRYN 171 QQFNRYPYT 188 402G3-VH SHFIH 189 WIYPGDDDTEYNHKFNG 190 RVEYYNGGFAY 191 402G3-VL KASKNIRNNLG 192 SGSTLQS 193 QQYDQYPLT 194 430H6-VH TYGMGVG 195 NIWWDDDKYYNPSLKN 196 HPLPGYKDNYVVDA 197 430H6-VL RSSQSLEYSDQYTYLE 198 GVSNRFS 199 FQATHDPYT 200 485G10-VH DYYIH 92 RIDPEDGETKYAPKFQG 78 YHGYWALDY 95 485G10-VL KTSQNVGTNVA 96 STSYRYS 97 HQYFSYPYT 98 487E3-VH DCYIH 201 RIDPEDGETKYAPKFQA 202 HCNFLYFDY 203 487E3-VL KASQNVGTIVA 204 SASYRSS 205 QQYNNYPVI 206

In some embodiments, the VH CDR1, CDR2, and CDR3 are selected from any set of VH CDR1, CDR2, and CDR3 shown in Table A, and the VL CDR1, CDR2, and CDR3 are selected from any set of VL CDR1, CDR2, and CDR3 shown in Table A. In some embodiments, the VH CDR1, CDR2, and CDR3 and the VL CDR1, CDR2, and CDR3 are selected from those derived from the same antibody in the examples.

In some embodiments, at least one, or two, or three, or four, or five, or six of the VH CDR1, CDR2, and CDR3 and the VL CDR1, CDR2, and CDR3 of the above are modified by one, two or three amino acid additions, deletions, substitutions, or the combinations thereof.

In one embodiment, the anti-IFNAR1 antibody or fragment thereof includes the following CDRs: HCDR1: DYYMH (SEQ ID NO: 77), HCDR2: RIDPEDGETKYAPKFQG (SEQ ID NO: 78), HCDR3: GGNFYVMDY (SEQ ID NO: 80), LCDR1: KASQNVGTNVV (SEQ ID NO: 81), LCDR2: SASYRVS (SEQ ID NO: 82), and LCDR3: QQKNNYPYT (SEQ ID NO: 83).

In one embodiment, one or more of the amino acid residues in the CDRs are substituted with a different amino acid to avoid post-translational modification. An example anti-IFNAR1 antibody or fragment thereof includes the following CDRs: HCDR1: DYYMH (SEQ ID NO: 77), HCDR2: RIDPEDAETKYAPKFQG (SEQ ID NO: 79), HCDR3: GGNFYVMDY (SEQ ID NO: 80), LCDR1: KASQNVGTNVV (SEQ ID NO: 81), LCDR2: SASYRVS (SEQ ID NO: 82), and LCDR3: QQKNNYPYT (SEQ ID NO: 83).

In some embodiments, the antibody is humanized but with one or more of the following back mutations on the heavy chain: 12V, 20L, 24G, 38K, 48I, 68A, 70I, 72A, 79A and 81L, according to Kabat numbering, and combinations thereof. In some embodiments, the antibody is humanized but with one or more of the following back mutations on the light chain: 4M, 13T, 21V, 43S, 46V, 74I, 78V and 87F according to Kabat numbering, and combinations thereof.

Non-limiting examples of heavy chain variable regions include SEQ ID NO: 7, and 84-87. Non-limiting example of light chain variable regions include SEQ ID NO: 8, and 88-91.

In some embodiments, the heavy chain variable region includes SEQ ID NO:85. In some embodiments, the light chain variable region includes SEQ ID NO:88.

In one embodiment, the anti-IFNAR1 antibody or fragment thereof includes the following CDRs: HCDR1: DYYIH (SEQ ID NO: 92), HCDR2: RIDPEDGETKYAPKFQG (SEQ ID NO: 93), HCDR3: YHGYWALDY (SEQ ID NO: 95), LCDR1: KTSQNVGTNVA (SEQ ID NO: 96), LCDR2: STSYRYS (SEQ ID NO: 97), and LCDR3: HQYFSYPYT (SEQ ID NO: C6).

In one embodiment, the anti-IFNAR1 antibody or fragment thereof includes the following CDRs: HCDR1: DYYIH (SEQ ID NO: 92), HCDR2: RIDPEDAETKYAPKFQG (SEQ ID NO:94), HCDR3: YHGYWALDY (SEQ ID NO: 95), LCDR1: KTSQNVGTNVA (SEQ ID NO: 96), LCDR2: STSYRYS (SEQ ID NO: 97), and LCDR3: HQYFSYPYT (SEQ ID NO: C6).

In some embodiments, the antibody is humanized but with one or more of the following back mutations on the heavy chain: 20L, 24G, 38K, 48I, 68A, 70I, 72A, 81L, and 97G, according to Kabat numbering, and combinations thereof. In some embodiments, the antibody is humanized but with one or more of the following back mutations on the light chain: 13T, 21V, 36Y, 46P, 78V, and 104L according to Kabat numbering, and combinations thereof.

Non-limiting examples of heavy chain variable regions include SEQ ID NO: 73, and 99-102. Non-limiting example of light chain variable regions include SEQ ID NO: 74, and 103-106.

In some embodiments, the heavy chain variable region includes SEQ ID NO:100. In some embodiments, the light chain variable region includes SEQ ID NO:105.

It was an interesting discovery that the presently prepared antibodies target an epitope that is different from known anti-IFNAR1 antibody Anifrolumab. Accordingly, in one embodiment, provided is an antibody or fragment thereof having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein, wherein the antibody or fragment thereof can bind to one or more amino acid residues selected from the group consisting of H273, L274, Y275, K276, and K278 of the IFNAR1 protein.

In some embodiments, the antibody or fragment can bind to at least two of these epitope residues, such as H273 and L274, H273 and Y275, H273 and K276, H273 and K278, L274 and Y275, L274 and K276, L274 and K278, Y275 and K276, Y275 and K278, or K276 and K278.

In some embodiments, the antibody or fragment can bind to at least two of these epitope residues, such as H273, L274, and Y275; H273, L274, and K276; H273, L274, and K278; H273, Y275, and K276; H273, Y275, and K278; H273, K276, and K278; L274, Y275, and K276; L274, Y275, and K278; L274, K276, and K278; and Y275, K276, and K278.

In some embodiments, the antibody or fragment can bind to at least four of these epitope residues, such as L274, Y275, K276, and K278; H273, Y275, K276, and K278; H273, L274, K276, and K278; H273, L274, Y275, and K278; and H273, L274, Y275, and K276.

In some embodiments, the antibody or fragment can bind to all of these epitope residues.

The CDRs, heavy chain variable regions and light chain variable regions of the present disclosure can be further modified. In some embodiments, the modified heavy chain variable region or light chain variable region retains at least about 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% sequence identity and is still capable of binding to IFNAR1.

In some embodiments, the modification is substitution at no more than one hot spot position from each of the CDRs. In some embodiments, the modification is substitution at one, two or three such hot spot positions. In one embodiment, the modification is substitution at one of the hot spot positions. Such substitutions, in some embodiments, are conservative substitutions.

A “conservative amino acid substitution” is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art, including basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, a nonessential amino acid residue in an immunoglobulin polypeptide is preferably replaced with another amino acid residue from the same side chain family. In another embodiment, a string of amino acids can be replaced with a structurally similar string that differs in order and/or composition of side chain family members.

Non-limiting examples of conservative amino acid substitutions are provided in the table below, where a similarity score of 0 or higher indicates conservative substitution between the two amino acids.

Amino Acid Similarity Matrix

C G P S A T D E N Q H K R V M I L F Y W W −8 −7 −6 −2 −6 −5 −7 −7 −4 −5 −3 −3 2 −6 −4 −5 −2 0 0 17 Y 0 −5 −5 −3 −3 −3 −4 −4 −2 −4 0 −4 −5 −2 −2 −1 −1 7 10 F −4 −5 −5 −3 −4 −3 −6 −5 −4 −5 −2 −5 −4 −1 0 1 2 9 L −6 −4 −3 −3 −2 −2 −4 −3 −3 −2 −2 −3 −3 2 4 2 6 I −2 −3 −2 −1 −1 0 −2 −2 −2 −2 −2 −2 −2 4 2 5 M −5 −3 −2 −2 −1 −1 −3 −2 0 −1 −2 0 0 2 6 V −2 −1 −1 −1 0 0 −2 −2 −2 −2 −2 −2 −2 4 R −4 −3 0 0 −2 −1 −1 −1 0 1 2 3 6 K −5 −2 −1 0 −1 0 0 0 1 1 0 5 H −3 −2 0 −1 −1 −1 1 1 2 3 6 Q −5 −1 0 −1 0 −1 2 2 1 4 N −4 0 −1 1 0 0 2 1 2 E −5 0 −1 0 0 0 3 4 D −5 1 −1 0 0 0 4 T −2 0 0 1 1 3 A −2 1 1 1 2 S 0 1 1 1 P −3 −1 6 G −3 5 C 12

Conservative Amino Acid Substitutions

For Amino Acid Substitution With Alanine D-Ala, Gly, Aib, β-Ala, L-Cys, D-Cys Arginine D-Arg, Lys, D-Lys, Orn D-Orn Asparagine D-Asn, Asp, D-Asp, Glu, D-Glu Gln, D-Gln Aspartic Acid D-Asp, D-Asn, Asn, Glu, D-Glu, Gln, D-Gln Cysteine D-Cys, S-Me-Cys, Met, D-Met, Thr, D-Thr, L-Ser, D-Ser Glutamine D-Gln, Asn, D-Asn, Glu, D-Glu, Asp, D-Asp Glutamic Acid D-Glu, D-Asp, Asp, Asn, D-Asn, Gln, D-Gln Glycine Ala, D-Ala, Pro, D-Pro, Aib, β-Ala Isoleucine D-Ile, Val, D-Val, Leu, D-Leu, Met, D-Met Leucine Val, D-Val, Met, D-Met, D-Ile, D-Leu, Ile Lysine D-Lys, Arg, D-Arg, Orn, D-Orn Methionine D-Met, S-Me-Cys, Ile, D-Ile, Leu, D-Leu, Val, D-Val Phenylalanine D-Phe, Tyr, D-Tyr, His, D-His, Trp, D-Trp Proline D-Pro Serine D-Ser, Thr, D-Thr, allo-Thr, L-Cys, D-Cys Threonine D-Thr, Ser, D-Ser, allo-Thr, Met, D-Met, Val, D-Val Tyrosine D-Tyr, Phe, D-Phe, His, D-His, Trp, D-Trp Valine D-Val, Leu, D-Leu, Ile, D-Ile, Met, D-Met

It will also be understood by one of ordinary skill in the art that antibodies as disclosed herein may be modified such that they vary in amino acid sequence from the naturally occurring binding polypeptide from which they were derived. For example, a polypeptide or amino acid sequence derived from a designated protein may be similar, e.g., have a certain percent identity to the starting sequence, e.g., it may be 60%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to the starting sequence.

In certain embodiments, the antibody comprises an amino acid sequence or one or more moieties not normally associated with an antibody. Exemplary modifications are described in more detail below. For example, an antibody of the disclosure may comprise a flexible linker sequence, or may be modified to add a functional moiety (e.g., PEG, a drug, a toxin, or a label).

Antibodies, variants, or derivatives thereof of the disclosure include derivatives that are modified, i.e., by the covalent attachment of any type of molecule to the antibody such that covalent attachment does not prevent the antibody from binding to the epitope. For example, but not by way of limitation, the antibodies can be modified, e.g., by glycosylation, acetylation, pegylation, phosphorylation, phosphorylation, amidation, derivatization by known protecting/blocking groups, proteolytic cleavage, linkage to a cellular ligand or other protein, etc. Any of numerous chemical modifications may be carried out by known techniques, including, but not limited to specific chemical cleavage, acetylation, formylation, metabolic synthesis of tunicamycin, etc. Additionally, the antibodies may contain one or more non-classical amino acids.

In some embodiments, the antibodies may be conjugated to therapeutic agents, prodrugs, peptides, proteins, enzymes, viruses, lipids, biological response modifiers, pharmaceutical agents, or PEG.

The antibodies may be conjugated or fused to a therapeutic agent, which may include detectable labels such as radioactive labels, an immunomodulator, a hormone, an enzyme, an oligonucleotide, a photoactive therapeutic or diagnostic agent, a cytotoxic agent, which may be a drug or a toxin, an ultrasound enhancing agent, a non-radioactive label, a combination thereof and other such agents known in the art.

Bi-Functional Molecules

It is contemplated that binding of both the IFNAR1 and another protein involved in the immune system would be advantageous or even synergistic. Accordingly, in some embodiments, bi-functional molecules are provided, such as a bispecific antibody with an anti-IFNAR1 fragment as disclosed herein and another antigen-binding fragment/portion.

The second portion of the bi-functional molecule may be any one of the following, (1) targeting B cells, including targeting B cell growth and survival factor such as anti-BAFF fragment, TACI-Ig; targeting surface molecules of B cells, such as anti-CD20 and anti-CD22 antibody fragments; (2) targeting co-stimulatory molecules, such as CTLA4-Ig and anti-CTLA4 antibody fragment; (3) targeting T cells, such as Edratide (hCDR1); and (4) targeting cytokines and complements, such anti-IL6, anti-CXCL13 and anti-05 antibody fragments.

In particular it is contemplated that the IFNAR1 and the BAFF (B-cell-activating factor) pathways can have synergistic effect in treating autoimmune diseases and disorders, such as lupus. Various formats of anti-IFNAR1/anti-BAFF bispecific antibodies (illustrated in FIG. 7) were tested for their binding capabilities and biological functions. Surprisingly, these bispecific antibodies exhibited comparable binding activity to monospecific 8G11 in blocking IFNα2b signaling, and even better activity in blockade of BAFF-induced B cell proliferation.

In one embodiment, therefore, provided is a bi-functional molecule having a first antigen-binding portion having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein and a second antigen-binding portion having specificity to a human B-cell-activating factor (BAFF) protein. The anti-IFNAR1 portion can a fragment of any embodiment of the present disclosure. The anti-BAFF portion can be a fragment from Belimumab (see, e.g., Dubey A K, et al., Journal of Pharmacology & Pharmacotherapeutics. 2011; 2(4):317-319).

The bi-functional molecule can take a format as illustrated in FIG. 7, e.g., having a full antibody fused to two single chain fragments (scFv) or to two Fab fragments. Other formats of bi-functional or bispecific molecules are also provided. In some embodiments, each of the anti-IFNAR1 and anti-BAFF fragments is independently selected from a Fab fragment, a single-chain variable fragment (scFv), or a single-domain antibody. In some embodiments, the bispecific antibody further includes a Fc fragment.

Polynucleotides Encoding the Antibodies and Methods of Preparing the Antibodies

The present disclosure also provides isolated polynucleotides or nucleic acid molecules encoding the antibodies, variants or derivatives thereof of the disclosure. The polynucleotides of the present disclosure may encode the entire heavy and light chain variable regions of the antigen-binding polypeptides, variants or derivatives thereof on the same polynucleotide molecule or on separate polynucleotide molecules. Additionally, the polynucleotides of the present disclosure may encode portions of the heavy and light chain variable regions of the antigen-binding polypeptides, variants or derivatives thereof on the same polynucleotide molecule or on separate polynucleotide molecules.

Methods of making antibodies are well known in the art and described herein. In certain embodiments, both the variable and constant regions of the antigen-binding polypeptides of the present disclosure are fully human Fully human antibodies can be made using techniques described in the art and as described herein. For example, fully human antibodies against a specific antigen can be prepared by administering the antigen to a transgenic animal which has been modified to produce such antibodies in response to antigenic challenge, but whose endogenous loci have been disabled. Exemplary techniques that can be used to make such antibodies are described in U.S. Pat. Nos. 6,150,584; 6,458,592; 6,420,140 which are incorporated by reference in their entireties.

Treatment and Diagnostic Methods

As described herein, the antibodies, variants or derivatives of the present disclosure may be used in certain treatment and diagnostic methods.

The present disclosure is further directed to antibody-based therapies which involve administering the antibodies of the disclosure to a patient such as an animal, a mammal, and a human for treating one or more of the disorders or conditions described herein. Therapeutic compounds of the disclosure include, but are not limited to, antibodies of the disclosure (including variants and derivatives thereof as described herein) and nucleic acids or polynucleotides encoding antibodies of the disclosure (including variants and derivatives thereof as described herein).

One embodiment provides a method of suppressing an immune response in a patient in need thereof. The method entails administering to the patient an antibody, fragment, or bi-functional molecule of the present disclosure. In some embodiments, the patient is a tissue or organ transplant recipient.

In some embodiments, a method of treating an autoimmune disease or disorder is provided. Non-limiting examples of autoimmune disease or disorder include type 1 diabetes, rheumatoid arthritis (RA), psoriasis/psoriatic arthritis, multiple sclerosis, systemic lupus erythematosus (lupus), inflammatory bowel disease, Addison's disease, Graves' disease, Sjögren's syndrome, Hashimoto's thyroiditis, myasthenia gravis, vasculitis, pernicious anemia, and celiac disease.

In a particular embodiments, the method is useful for treating systemic lupus erythematosus (lupus).

A specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the particular antibodies, variant or derivative thereof used, the patient's age, body weight, general health, sex, and diet, and the time of administration, rate of excretion, drug combination, and the severity of the particular disease being treated. Judgment of such factors by medical caregivers is within the ordinary skill in the art. The amount will also depend on the individual patient to be treated, the route of administration, the type of formulation, the characteristics of the compound used, the severity of the disease, and the desired effect. The amount used can be determined by pharmacological and pharmacokinetic principles well known in the art.

Methods of administration of the antibodies, variants or include but are not limited to intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural, and oral routes. The antigen-binding polypeptides or compositions may be administered by any convenient route, for example by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (e.g., oral mucosa, rectal and intestinal mucosa, etc.) and may be administered together with other biologically active agents. Thus, pharmaceutical compositions containing the antigen-binding polypeptides of the disclosure may be administered orally, rectally, parenterally, intracistemally, intravaginally, intraperitoneally, topically (as by powders, ointments, drops or transdermal patch), bucally, or as an oral or nasal spray.

The term “parenteral” as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous and intra-articular injection and infusion.

Administration can be systemic or local. In addition, it may be desirable to introduce the antibodies of the disclosure into the central nervous system by any suitable route, including intraventricular and intrathecal injection; intraventricular injection may be facilitated by an intraventricular catheter, for example, attached to a reservoir, such as an Ommaya reservoir. Pulmonary administration can also be employed, e.g., by use of an inhaler or nebulizer, and formulation with an aerosolizing agent.

It may be desirable to administer the antigen-binding polypeptides or compositions of the disclosure locally to the area in need of treatment; this may be achieved by, for example, and not by way of limitation, local infusion during surgery, topical application, e.g., in conjunction, with a wound dressing after surgery, by injection, by means of a catheter, by means of a suppository, or by means of an implant, said implant being of a porous, non-porous, or gelatinous material, including membranes, such as sialastic membranes, or fibers. Preferably, when administering a protein, including an antibody, of the disclosure, care must be taken to use materials to which the protein does not absorb.

Methods of detecting expression of a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein in a sample are also provided, in some embodiments, comprising contacting the sample with the antibody or fragment thereof, and detecting the binding which indicates expression of IFNAR1 in the sample.

Compositions

The present disclosure also provides pharmaceutical compositions. Such compositions comprise an effective amount of an antibody, and an acceptable carrier. In some embodiments, the composition further includes a second anticancer agent (e.g., an immune checkpoint inhibitor).

In a specific embodiment, the term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. Further, a “pharmaceutically acceptable carrier” will generally be a non-toxic solid, semisolid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type.

The term “carrier” refers to a diluent, adjuvant, excipient, or vehicle with which the therapeutic is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water is a preferred carrier when the pharmaceutical composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. Suitable pharmaceutical excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents such as acetates, citrates or phosphates. Antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; and agents for the adjustment of tonicity such as sodium chloride or dextrose are also envisioned. These compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations and the like. The composition can be formulated as a suppository, with traditional binders and carriers such as triglycerides. Oral formulation can include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Examples of suitable pharmaceutical carriers are described in Remington's Pharmaceutical Sciences by E. W. Martin, incorporated herein by reference. Such compositions will contain a therapeutically effective amount of the antigen-binding polypeptide, preferably in purified form, together with a suitable amount of carrier so as to provide the form for proper administration to the patient. The formulation should suit the mode of administration. The parental preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

In an embodiment, the composition is formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous administration to human beings. Typically, compositions for intravenous administration are solutions in sterile isotonic aqueous buffer. Where necessary, the composition may also include a solubilizing agent and a local anesthetic such as lignocaine to ease pain at the site of the injection. Generally, the ingredients are supplied either separately or mixed together in unit dosage form, for example, as a dry lyophilized powder or water free concentrate in a hermetically sealed container such as an ampoule or sachette indicating the quantity of active agent. Where the composition is to be administered by infusion, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline. Where the composition is administered by injection, an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration.

The compounds of the disclosure can be formulated as neutral or salt forms. Pharmaceutically acceptable salts include those formed with anions such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc., and those formed with cations such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylamino ethanol, histidine, procaine, etc.

EXAMPLES Example 1. Generation of Mouse Monoclonal Antibodies Against Human IFNAR-1

This example shows generation of anti-human-IFNAR-1 mouse monoclonal antibodies using the hybridoma technology.

Immunization

Recombinant human IFNAR-1 proteins containing the entire extracellular region of human IFNAR-1 were used as the immunogen to raise anti-human IFNAR-1 antibodies. C57BL/6, Balb/c, SJL mice or SD rats were first immunized subcutaneously (s.c.) with 50 μg immunogen and then immunized intraperitoneally (i.p.). or s.c. biweekly with 25 μg immunogen. Immune response was monitored by retroorbital bleeds. Plasma was screened by ELISA binding assay. In short, His-tagged IFNAR-1 was coated at 0.5 μg/ml overnight and then blocked by 5% BSA in PBS. Serial diluted sera were incubated with the coated antigen for 1 h at room temperature. The resulting plates were washed with PBS/T and incubated with goat anti-mouse IgG-HRP for 1 h at room temperature. The plates were developed with TMB substrate and analyzed by spectrophotometer at OD 450-630 nm. The mice with high titers of anti-IFNAR1 immunoglobulin were selected for fusion and further screening. Three days prior to sacrifice and removal of the spleens, the mice were final boosted i.p. with 25 μg antigen. The spleens were used for fusion.

Fusion and Hybridoma Screening

The mouse splenocytes, isolated from the mice, were fused with a mouse myeloma cell line based upon standard protocols. Single cell suspensions of splenic lymphocytes from immunized mice were fused to one-third the number of SP2/0 non secreting mouse myeloma cells with electrofusion machine. Cells were plated at approximately 1*10E5/well in flat bottom microtiter plate, followed by about 10 days incubation in selective medium containing 1*HAT, 10% fetal bovine serum, in DMEM. After 10 days, cells were cultured in medium in which the HAT was replaced with HT. Individual wells were then screened by ELISA for mouse anti-IFNAR-1 monoclonal IgG antibodies. The antibody secreting hybridomas were changed medium and screened again after 2 days. If still positive for mouse anti-IFNAR-1 antibodies, hybridoma were sub cloned twice by limiting dilution. The stable sub clones were then cultured in vitro to generate small amount of antibody in tissue culture medium for further characterization with various functional assays.

Clones showing strong blocking ability in IFN-responsive reporter assay were selected for sub cloning. Supernatants of 2-round sub clone were used to confirm ELISA-based human and rhesus IFNAR-1 binding and IFN alpha blocking ability, followed by sequencing and further analysis. After these screenings, 38 clones (4A6, 4B12, 4D8, 8G11, 12G11, 17F9, 18B6, 18C1, 19B6, 20B3, 20E10, 20E12, 21D6, 24F6, 29E12, 30B5, 3008, 34H8, 36E3, 39F5, 41F1, 46A10, 47C6, 47F5, 104A3, 106A7, 107E12, 124D12, 260H8, 268E9, 269A7,293H10, 370E5, 392D6, 402G3, 430H6, 485G10 and 487E3) were selected. Sequences of these clones are list in Table 1. Chimeric antibodies fused to human IgG1 Fc of these hybridoma were generated for further characterization.

TABLE 1 Antibody sequences selected from screening Anti- SEQ body ID chain Sequences* (CDR underlined and bold) NO: 4A6-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DYYMH 1 WVKQRTEQGLEWIG R IDPDDGETKYAPKFQG KATMTADTSSNTAYLQLGS LTSEDAAVYYCAR GG NYYVMDN WGQGTSVTVSS 4A6-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 2 WYQQKSGQSPKALIY T ASYRYS GVPDRFTGSGSGTDFTLTISNLQSEDLADYL C QQYFSYPHT FGG GTKLEIK 4B12-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DSYMH 3 WVKERTEQGLEWIG R IDPEDGETNYAPKFQG KATLTADTSSNTAYLQLSG LTSEDTAVYYCAR RV SSLYAMDY WGQGTSVTVSS 4B12-VL DIVMTQSQKSMSTSVGDRVSVTC KASQNVGTNVA 4 WYQQKPGQSPKPLIY L ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQYNNYPWT FGG GTKLEIK 4D8-VH EVRLQQSGAELVQPGASVKLSCTGFGFNIK DYYMH 5 WVKQRTEQGLEWIG R IDPEDAETKYAPKFQG QATITADTSSNTAYVQVSSL SSEDTAVYYCAR GG NFYVMDY WGQGTSVTVSS 4D8-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVV 6 WYQQKPGQSPKVLIY S ASYRYS GVPDRFTGSGSGTDFTLIISNVQSEDLAEYF C QQKNSYPYT FGG GTKLEIK 8G11-VH EVQLQQSGAELVKPGASVKLSCTGFGFNIK DYYMH 7 WVKQRAEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQVSSL TSEDTAVYYCAR GG NFYVMDY WGQGTSVTVSS 8G11-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVV 8 WYQQKPGQSPKVLIY S ASYRVS GVPDRFTGSGSGTDFTLIISNVQSEDLAEYF C QQKNNYPYT FGG GTKLEIK 12G11-VH AVQLQQSGAELVKPGASVKLSCTASGFNIK DYYMH 9 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLSSL TSEDTAVYYCAR GG NYYAMDY WGQGTSVTVSS 12G11-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 10 WYQQKPGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQHNSYTYK FGG GTKVEIK 17F9-VH EVQLLQSWADLVKPGASVKLSCTASGFNIK DYYIH 11 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQD KAAITADTSSNTAYLQLSSL TSEGTAVYYCAR YD GYYGFDY WGQGTTLTVSS 17F9-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 12 WYQQKPGQSPKPLIY S TSYRYS GVPDRFTGSGSGTDFTLTITNVQSEDLAEYF C HQYNNYPYT FGG GTKLEIK 18B6-VH EVQLQQSGAKLVKPGASVKLSCTASGFNIK DYYMC 13 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTASLQLSSL TSEDTAVYYCAR GG NYYAMDY WGQGTSVTVSS 18B6-VL DTVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 14 WYQQKPGQSPKALIY S ATYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQHNSYSYT FGG GTKLEIK 18C1-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DYYMH 15 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLSSL TSEDTAVYYCAR LG NWVFDY WGQGTTLTVSS 18C1-VL DTVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVD 16 WYQQKSGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQYNTYT FGGGT KLEIK 19B6-VH EVQLQQFGAELVKPGASVKLSCTASGFNIK DYYMH 17 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQV KATITADTSSNTAYLHFSSL TSEDTAVYYCVR GG NFYYFDY WGQGTTLTVSS 19B6-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 18 WYQQKPGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQCINYPYT FGG GTKLEIK 20B3-VH EVHLQQSGAELVKPGTSLKLSCTASGFNIK DYYIH W 19 VKQRTEQGLEWIG R IDPEDGETKYAPTFQG KATITADTSSNTAYLQLSSL TSEDTAVYYCAR YN GYSGFDY WGQGTTLTVSS 20B3-VL DIVMTQSQKFMSTSEGDRVSVTC KASQNVGTNVV 20 WYQQKPGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQYNRYPFT FGA GTKLELK 20E10-VH EVQLLQSWADLVKPGASVKLSCTASGFNIK DYYIH 21 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQD KAAITADTSSNTAYLQLSSL TSEGTAVYYCAR YD GYYGFDY WGQGTTLTVSS 20E10-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 22 WYQQKPGQSPKPLIY S TSYRYS GVPDRFTGSGSGTDFTLTITNVQSEDLAEYF C HQYNNYPYT FGG GTKLEIK 20E12-VH EVQLQQSGAEVVKPGASVKLSCTASGFNIK DYYMH 23 WVKQRTEQGLECIG R IDPEDGETKYVPKFQG KATITAETSSNTAYLQLSSL TAEDTAVYYCSR GG SYYVMDY WGQGTSVTVSS 20E12-VL DVVMTQSRKFMSTSVGDRVSVTC KASQNVGTSVA 24 WYQQKLGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQDNSYPHT FGG GTKLEIK 21D6-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DYYMH 25 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLSSL TSEDTAVYYCTS LH WSLDS WGQGTTLTVSS 21D6-VL DIVMTQSQKFMSTTVGDRVSITC KASQNVGTAVA W 26 YQQQPGQSPKPLIY S TANRDT GVPDRFTGSGSGTDFTLTISNMQSEDLAHY FC QQYSSYPYT FGG GTKLEIK 24F6-VH DVQLQQSGAELVKPGASVNLSCTGSGFNIK DYYIH 27 WVKQRTEQGLEWIG R VDPEDGETKYVPKFLD KATITADTSSNTAYLQLSSL TSEDTAVYYCTR GG NYYAMDY WGQGTSVTVSS 24F6-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 28 WYQQKSGQSPKALIF L ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQCNNYRLT FGS GTKLEIK 29E12-VH EVQLLQSWADLVKPGASVKLSCTASGFNIK DYYIH 29 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQD KAAITADTSSNTAYLQLSSL TSEGTAVYYCAR YD GYYGFDY WGQGTTLTVSS 29E12-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 30 WYQQKPGQSPKPLIY S TSYRYS GVPDRFTGSGSGTDFTLTITNVQSEDLAEYF C HQYNNYPYT FGG GTKLEIK 30B5-VH EAQLQQSGAELVKPGASVKLSCTASGFNIR DSYIH W 31 VNQRTEQGLEWIG R IDPEDGETKYAPKFQG KATMTADTSSNTAYLQLSS LTSEDTAVYYCAS WL ADYSAMDN WGQGTSVTVSS 30B5-VL DIQMTQSSSSFSVSLGDRVTITC KASEDIYNRLA WY 32 QQKPGNAPRLLIS G ATSLET GVPSRFSGSGSGKDYTLSITSLQTEDVATYY C QQYWNTLYT FGG GTKLEMK 3008-VH EVQLQQSGAELVKPGASVKLSCTSSGFNIK DSYMH 33 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLNSL TSEDTAVYYCAR RG SSLYAVDY WGQGTSVTVSS 3008-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTSVA 34 WYQQKPGQSPKAVIY L ASYRHR GVPARFTGSGSGTDFTLTISNVQSEDLAEY FC QQFNIYPWT FGG GTKLEIK 34H8-VH EVQLLQSGAELVKPGASVRLSCTASGFNIK DYYLH 35 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITTDTSSNTAYLQLSSL TSEDTAVYYCTR GG NYDVMDY WGQGTSVTVSS 34H8-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTYVV 36 WYQQKPGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTIGNVQSEDLAEYF C QQKNTYPFT FGG GTKLEIE 36E3-VH EVQLQQSGAELVKPGASVKLSCTSSGFNIK DSYMH 37 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLNSL TSEDTAVYYCAR RG SSLYAVDY WGQGTSVTVSS 36E3-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTSVA 38 WYQQKPGQSPKAVIY L ASYRHR GVPARFTGSGSGTDFTLTISNVQSEDLAEY FC QQFNIYPWT FGG GTKLEIK 39F5-VH EVQLQQSGADLVRPGASVKLSCTASGFNIK DYYIH W 39 VKQRTEQGLEWIG R IDPEDGETKYAPKFQV KTTITADTSSNTAYLQFSSL TSEDTAVYYCVR GG NFYYFDY WGQGSTLTVSS 39F5-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 40 WYQQKPGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQCINYPYT FGG GTKLEIK 41F1-VH EVQLQQSGAELVKSGASVRLSCTASGFNIK DYYMH 41 WVKQRTEKGLEWIG R IDPEDGETKYVPKFQG KATITADTSSNTVYLQLNSL TSEDTAVYYCVR GG NYYVMDY WGQGTSVTVSS 41F1-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTYVA 42 WYQQKPGQSPKVVIY S ASYRYN GVPDRFTGSGSGTDFTLTISNVQPEDLAEYF C QQYNNYPLT FGS GTKLEIK 46A10-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DYYMH 43 WVKQRTEQGLELIG R IDPEDGETKYAPKFQV KATITADASSNTAYLQFSSL TSEDAAVYYCVR GG NFYYFDF WGQGTTLTVSS 46A10-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 44 WYQQKPGQSPKALVY S ASYRYS GVPDRFTGSGSGTDFTLTISDVQSEDLAEYF C QQCINYPYT FGG GTKLEIK 47C6-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DYYIH W 45 VKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLHLSSL TSEDTAVYYCSR GG NFYYFDY WGQGTSLTVSS 47C6-VL DIVMTQSQKFMSTLVGDRVSVTC KASQNVGTNVA 46 WYQQKPGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQCNSYSYT FGG GTKLEIK 47F5-VH EVQLQQSGAEVVKPGASVKLSCTASGFNIK DYYMH 47 WVKQRTEQGLECIG R IDPEDGETKYVPKFQG KATITAETSSNTAYLQLSSL TAEDTAVYYCSR GG SYYVMDY WGQGTSVTVSS 47F5-VL DVVMTQSRKFMSTSVGDRVSVTC KASQNVGTSVA 48 WYQQKLGQSPKALIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQDNSYPHT FGG GTKLEIK 104A3-VH EVQLQQSGAELVKPGASVKVSCTGSGFNIK DYYIH 49 WVKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITSDTSSNTAYLQLSSL TSGDTAVYFCAR YD GYYCFDY WGQGTTLTVSS 104A3-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 50 WYQQKPGQSPKPLIY S TSYRYS GVPDRFTGSGSGTDFTLTISNVQSADLAAYF C QQYNNYPYT FGG GTRLEIK 106A7-VH EVQLQQSGADLVKPGASVKLSCTTSGFNIK DYYMH 51 WVNQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLSSL TSEDTAVYYCAR DW GHSFDY WGQGTTLTVSS 106A7-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTTVA 52 WYQQKPGQSPKTLIY S ASYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQYNSYT FGGGT KLEMK 107E12- EVQLQQSGAEFVKPGASVKLSCTASGFNIK DYYIH W 53 VH VTQKTEQGLEWIG R IDPEDGETKYAPKFQD KATITADSSSNTAYLQLSSL TSVDTAVYFCSR EG SFTGWFPY WGQGTLVSVSA 370E5-VL DIVMTQSQKFMSTSVGDRVSVTC KARQSVGTYVA 54 WYQQKPGQSPKALIY S TSYRYN GVPDRFTGSGSGTDFTLTISNVQSEDLADY F CQQYHSYPYT FGG GTKLEIK 124D12- EVQLQQSGAELVKPGASVKVSCTGSGFNIK DYYIH 55 VH WVKQRTEQGLEWIG R IDPEDGETKYAPKFQ GRATITSDTSSNTAYLQLSSL TSGDTAVYYCAR YD GYYCFDY WGQGTTLTVSS 124D12- DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 56 VL WYQQKPGQSPKPLIY S TSYRYS GVPDRFTGSGSGTDFTLTISNVQSADLAAYF C QQYNNYPYT FGG GTRLEIK 260H8-VH EVQLQESGPGLAKPSQTLSLTCSVTGYSIT SDYWN W 57 IRKFPGNKLEYMG Y ISYSGSIYYNPSLKS RISITRDTSKNQYYLQLNSVTNE DTATYYCAR SGG MYYFDY WGQGTTLTVSS 260H8-VL DIQMTQSPASLSASVGETVTITC RASGNIHNYLA WY 58 QQKQGKSPQLLVY N AKTLED GVPSRFSGSGSGTQYSLKINSLQPEDFGSYY C QHFWSIPPT FGS GTKLEIK 268E9-VH EVQLQESGPGLAKPSQTLSLTCSVTGYSIT SDYWN W 59 IRKFPGNKLEYMG Y ISYSGSIYYNPSLKS RISITRATSKNQYYLQLNSVTNE DTATYYCAR SGG MYYFDY WGQGTTLTVSS 268E9-VL DIQMTQSPASLSASVGETVTITC RASGNIHNYLA WY 60 QQKQGKSPQLLVY N AKTLED GVPSRFSGSGSGTQYSLKINSLQPEDFGSYY C QHFWSIPPT FGS GTKLEIK 269A7-VH EVQLQESGPGLAKPSQTLSLTCSVTGYSIT SDYWN W 61 IRKFPGNKLEYMG Y ISYSGTIYYNPSLKS RISITRDTSKNQYYLQLNSVTN EDTATYYCAR SGG MYYFDY WGQGTTLTVSS 269A7-VL DIQMTQSPASLSASVGETVTITC RASGNIHNYLA WY 62 QQKQGKSPQLLVY N AKTLED GVPSRFSGSGSGTQYSLKINSLQPEDFGSYY C QHFWSIPPT FGS GTKLEIK 293H10- EVQLQESGPGLAKPSQTLSLTCSVTGYSIT SDYWN W 63 VH IRKFPGNKLEYMG Y ISYSGNTDYNPSLKS RFSITRDTSKNQFYLQLNSVTT EDTATYYCAR SEG MYFFDY WGQGTTLTVSS 293H10- DIQMTQSPASLSASVGETVSITC RASGNIHNYLA WY 64 VL HQKQGKSPQLLVY N AKTLAD GVPSRFSGSGSGTQYSLKINSLQPEDFGSY YC QHFWSTPPT FGS GTKLEIK 370E5-VH EVQLQQSGAELVKPGASVKLSCTASGFNIK DYYIH W 65 VKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLSSL TSEDTAVYYCAR FG GLTAMDY WGQGTSVTVSS 370E5-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 66 WYQQKPGQSPKALIY A TSYRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQYNNYPYT FGG GTKLEIK 392D6-VH AVQLQQSGTELVKPGASVKLSCSASGFNIK DYYVH 67 WVKQKTEQGLEWIG R IDPEDGETKYAPKFQG KATVTADTSSNTAYMQLSS LTSEDTAVYYCTR FG GLDAMDY WGQGTSVTVSS 392D6-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA 68 WYQQKPGQSPKPLIY S TSYRYN GVPDRFTGSGSGTEFTLTISNVQSEDLAEYF C QQFNRYPYT FGG GTKLEIK 402G3-VH QVQLQQSGAELVKPGSSVKISCKASGFTFT SHFIH WI 69 KQQPGNGLKWIG W IYPGDDDTEYNHKFNG KATLTADKSSSTAYMHLSS LTSEDSAVYFCAR RV EYYNGGFAY WGQGTLVTVSS 402G3-VL DVQMTQSPSYLAAPPGESVSISC KASKNIRNNLG WY 70 QERPGKTPNLLIH S GSTLQS GAPSRFSGGGSGTDFTLTIRSLESEDSAVYY C QQYDQYPLT FGS GTKLEIK 430H6-VH QVTLKESGPGILQPSQTLSLTCTFSGFSLN TYGMGV 71 G WIRQPSGKGLEWL A NIWWDDDKYYNPSLKN RLTISKDTSNNQAFLKIT NVDTADTATYFCAR H PLPGYKDNYVVDAWGQGASVTVSS 430H6-VL DVVLTQTPGSLSVTLGDQASISC RSSCISLEYSDQYT 72 YLE WYLQKSGQSPQ LLIY GVSNRFS GVPDRFIGSGSGTDFTLKISRVEPEDL GVYYC FQATHDP YT FGAGTKLELK 485G10- EVQLQQSGAELVKPGASVKLSCTGSGFNIK DYYIH W 73 VH VKQRTEQGLEWIG R IDPEDGETKYAPKFQG KATITADTSSNTAYLQLSSL TSEDTVVYYCGR YH GYWALDY WGQGTSVTVSS 485G10- DIVMTQSQKFMSTSVGDRVSVTC KTSQNVGTNVA 74 VL WYQQKPGQSPKPLIY S TSYRYS GVPDRFTGSGSGTDFTLIISNVQSEDLAEYF C HQYFSYPYT FGG GTLLEIK 487E3-VH EVQLQQSGAELVKPGASVKLSCSASGFNIK DCYIH W 75 VKQRTEQGLEWIG R IDPEDGETKYAPKFQA KATITADTSSNTAYLQLNSL TSEDTAVYYCAR HC NFLYFDY WGQGSTLTVS 487E3-VL DIVMTQSQKSMSTSLGDRVTVTC KASQNVGTIVA W 76 YQLKPGQSPKTLIY S ASYRSS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYF C QQYNNYPVI FGS GTKLEIR

Example 2. Binding Properties of Anti-IFNAR-1 Mouse Monoclonal Antibodies

This example tested the binding properties of the anti-IFNAR-1 mouse antibodies to the human IFNAR-1 proteins by ELISA assay. In short, His-tagged IFNAR-1 was coated at 0.5 μg/ml overnight and then blocked by 5% BSA in PBS. Serial diluted anti-IFNAR-1 antibodies were incubated with the coated antigen for 1 h at room temperature. The resulting plates were washed with PBS/T and incubated with goat anti-mouse IgG-HRP for 1 h at room temperature. The plates were developed with TMB substrate and analyzed by spectrophotometer at OD 450-630 nm. The results of the ELISA assays are summarized in Table 2, which shows EC₅₀ of binding to human IFNAR-1 protein.

TABLE 2 Binding EC₅₀(nM) on hIFNAR-1 protein. Antibody EC₅₀ (nM) Antibody EC₅₀ (nM) 4D8 0.067 269A7 0.476 8G11 0.069 293H10 0.097 34H8 0.064 370 E5 0.052 104A3 0.056 392D6 0.054 106A7 0.099 402G3 0.137 107 E12 0.075 430H6 0.733 124D12 0.062 485G10 0.015 260H8 0.055 487 E3 0.028 268 E9 0.088

Anti-IFNAR-1 Antibody BIACORE Analysis

The binding of the antibodies to recombinant His-tagged human IFNAR-1-ECD protein was examined by Biacore T200 using a capture method. The anti-IFNAR-1 antibodies were captured using anti-human Fc antibody or Protein A which were coated on chip. The serial concentrations of his-tagged human IFNAR-1-ECD protein (0-8 nM) were injected over capture antibodies at the flow rate of 30 μl/min. The dissociation phases were 600 s or 1200 s. The results are shown in Table 3 below. The Biacore results for the anti-IFNAR-1 antibodies demonstrate that these anti-IFNAR-1 antibodies are high affinity binders to human IFNAR-1.

TABLE 3 Binding of antibodies to recombinant IFNAR-1 protein Antibody ka (1/Ms) kd (1/s) KD (M) 4D8 2.31E+06 9.03E−05 3.90E−11 8G11 2.36E+06 6.40E−05 2.71E−11 34H8 2.37E+06 4.41E−05 1.86E−11

Example 3. IFN-Responsive Reporter Assay for Screening Anti-IFNAR-1 Mouse Monoclonal Antibodies

HEK-Blue™ IFNα/β cells (InvivoGen) are specifically designed to monitor the activation of the JAK-STAT pathway induced by type I IFNs. Upon IFN-α or IFN-β stimulation, these cells activate the JAK-STAT pathway and subsequently the expression of the reporter gene named secreted embryonic alkaline phosphatase (SEAP). SEAP which is secreted in the supernatant is easily detectable by using a SEAP detection reagent QUANTI-Blue™ (InvivoGen). A neutralizing antibody, which blocks interferon binding to its receptor, will inhibit IFN-induced reporter gene expression. This reporter assay was utilized for screening anti-IFNAR-1 mouse monoclonal antibodies.

HEK-Blue™ IFNα/β cells were incubated with 400 U/ml IFNα2b in the presence of serial dilutions of anti-IFNAR-1 mouse monoclonal antibodies overnight. The expression of reporter gene SEAP was determined by using a spectrophotometer at 650 nm. EC₅₀ of the tested antibodies are listed in Table 4. Among these antibodies, 4D8, 8G11, 34H8, 485G10 and 487E3 antibodies showed superior effects in blocking IFNα2b signal. Given the analysis on sequence homology, the clones of 8G11 and 485G10 were selected for further humanization and characterization.

TABLE 4 Reporter assay for the antibodies Clone ID EC₅₀ (nM) Clone ID EC₅₀(nM) 4D8 0.460 286E9 3.871 8G11 0.465 293H10 1.285 34H8 0.560 370E5 2.170 104A3 1.310 392D6 0.824 106A7 3.516 402G3 1.267 107E12 1.207 430H6 1.297 124D12 0.981 485G10 0.286 260H8 5.074 487E3 0.161 269A7 6.713

Example 4. Anti-IFNAR-1 mAb Humanization A. 8G11

The mouse antibody 8G11 variable region genes were employed to create a humanized MAb. In the first step of this process, the amino acid sequences of the VH and VK of 8G11 were compared against the available database of human Ig gene sequences to identify the overall best-matching human germline Ig gene sequences. For the heavy chain, the closest human match was the IGHV1-46*01 gene. For the light chain, the best human match was the IGKV1-9*01 gene.

Humanized variable domain sequences were then designed where the CDR1 (SEQ ID NO:77), 2 (SEQ ID NO:78), and 3 (SEQ ID NO:80) sequences of the 8G11 VH were grafted onto framework sequences of the IGHV1-46*01 gene and the CDR1 (SEQ ID NO:81), 2 (SEQ ID NO:82) and 3 (SEQ ID NO:83) of the 8G11 light chain were grafted onto framework sequences of the IGKV1-9*01 gene. A 3D model was then generated to determine if there were any framework positions where replacing the mouse amino acid to the human amino acid could affect binding and/or CDR conformation. In the case of the heavy chain, K12, V20, A24, R38, M48, V68, M70, R72, V79 and M81 (Kabat numbering) in human framework was identified and subjected to back-mutations to their moue counterpart amino acid i.e.: K12V, V20L, A24G, R38K, M48I, V68A, M70I, R72A, V79A and M81L. In the case of the light chain, L4, A13, 121, A43, L46, T74, L78 and Y87 (Kabat numbering) in human framework was identified and subjected to back-mutation to their moue counterpart amino acid i.e.: L4M, A13T, I21V, A43S, L46V, T74I, L78V and Y87F. At the meantime, G56 A mutation was employed to remove the PTM.

TABLE 5 8G11 sequences and CDRs Antibody chain SEQ ID or domain Sequences (CDR underlined and bold) NO: 8G11-VH EVQLQQSGAELVKPGASVKLSCTGFGFNIK DYYMH WVKQRAEQGLEWIG R 7 IDPEDGETKYAPKFQG KATITADTSSNTAYLQVSSLTSEDTAVYYCAR GG NFYVMDY WGQGTSVTVSS 8G11-VL DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVV WYQQKPGQSPKVLIY S 8 ASYRVS GVPDRFTGSGSGTDFTLIISNVQSEDLAEYFC QQKNNYPYT FGG GTKLEIK CDRH1 DYYMH 77 CDRH2 RIDPEDGETKYAPKFQG 78 CDRH2 RIDPED A ETKYAPKFQG 79 (modified) CDRH3 GGNFYVMDY 80 CDRL1 KASQNVGTNVV 81 CDRL2 SASYRVS 82 CDRL3 QQKNNYPYT 83

The humanized sequences are listed in Table 6: 8G11-VH1, 8G11-VH2, 8G11-VH3, 8G11-VH4, 8G11-VL1, 8G11-VL2, 8G11-VL3, and 8G11-VL4.

TABLE 6 Humanized sequences Antibody SEQ ID chain Sequences (CDR italic; back mutations bold and underlined) NO: 8G11-VH1 QVQLVQSGAEVKKPGASVKVSCKASGFNIK DYYMH WVRQAPGQGLEWMG R 84 IDPED

ETK YAPKFQGRVTMTRDTSTSTVYMELSSLRSEDTAVYYCAR GG NFYVMDY WGQGTLVTVSS 8G11-VH2 QVQLVQSGAEVVKPGASVKVSCKGSGFNIK DYYMH WVRQAPGQGLEWIG R 85 IDPED

ETKYAPKFQG RVTMTADTSTSTVYMELSSLRSEDTAVYYCAR GG NFYVMDY WGQGTLVTVSS 8G11-VH3 QVQLVQSGAEVVKPGASVKVSCKGSGFNIK DYYMH WVKQAPGQGLEWIG R 86 IDPED

ETKYAPKFQG RVTITADTSTSTVYLELSSLRSEDTAVYYCAR GG NFYVMDY WGQGTLVTVSS 8G11-VH4 QVQLVQSGAEVVKPGASVKLSCKGSGFNIK DYYMH WVKQAPGQGLEWIG R 87 IDPED

ETKYAPKFQG RATITADTSTSTAYLELSSLRSEDTAVYYCAR GG NFYVMDY WGQGTLVTVSS 8G11-VL1 DIQLTQSPSFLSASVGDRVTITC KASQNVGTNVV WYQQKPGKAPKLLIY S 88 ASYRVS GVPSRFSGSGSGTEFTLTISSLQPEDFATYYC QQKNNYPYT FGQ GTKLEIK 8G11-VL2 DIQLTQSPSFLSTSVGDRVTITC KASQNVGTNVV WYQQKPGKSPKVLIY S 89 ASYRVS GVPSRFSGSGSGTEFTLIISSLQPEDFATYYC QQKNNYPYT FGQ GTKLEIK 8G11-VL3 DIQLTQSPSFLSTSVGDRVTITC KASQNVGTNVV WYQQKPGKSPKVLIY S 90 ASYRVS GVPSRFSGSGSGTEFTLIISSVQPEDFATYFC QQKNNYPYT FGQ GTKLEIK 8G11-VL4 DIQMTQSPSFLSTSVGDRVTVTC KASQNVGTNVV WYQQKPGKSPKVLIY S 91 ASYRVS GVPSRFSGSGSGTEFTLIISSVQPEDFATYFC QQKNNYPY TFGQ GTKLEIK

All the 16 IgGs were expressed in the HEK293 cell line. Express antibodies were performed for affinity ranking. Detailed data of affinity ranking were summarized in Table 7.

TABLE 7 Affinity ranking of humanized antibodies. Antibody k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) VH4 + VL3 3.01E+05 8.52E−05 2.84E−10 VH2 + VL2 2.87E+05 9.42E−05 3.28E−10 VH4 + VL2 2.92E+05 9.69E−05 3.32E−10 VH3 + VL3 3.01E+05 1.10E−04 3.64E−10 VH2 + VL3 2.65E+05 9.65E−05 3.64E−10 VH4 + VL4 2.83E+05 1.05E−04 3.72E−10 VH2 + VL4 2.62E+05 1.02E−04 3.88E−10 VH3 + VL2 2.84E+05 1.11E−04 3.89E−10 VH3 + VL4 2.81E+05 1.13E−04 4.01E−10 VH3 + VL1 2.56E+05 1.06E−04 4.13E−10 VH2 + VL1 2.02E+05 8.84E−05 4.39E−10 VH4 + VL1 2.03E+05 9.94E−05 4.89E−10 VH1 + VL1 1.48E+05 9.83E−05 6.62E−10 VH1 + VL2 1.67E+05 1.27E−04 7.65E−10 VH1 + VL4 1.69E+05 1.41E−04 8.36E−10 VH1 + VL3 2.31E+05 2.00E−04 8.65E−10

Based on the affinity ranking results, 4 IgGs (VH4+VL3, VH2+VL2, VH2+VL1, VH1+VL1) were expressed and purified. The purified antibodies were further selected for affinity measurement under different concentrations. Detailed data were summarized in Table 8.

TABLE 8 Affinity of selected humanized antibodies. Antibody ka (1/Ms) kd (1/s) KD (M) 8G11-H4L3 3.40E+05 7.47E−05 2.20E−10 8G11-H2L2 2.98E+05 1.25E−04 4.19E−10 8G11-H2L1 2.29E+05 9.24E−05 4.03E−10 8G11-H1L1 1.61E+05 2.19E−04 1.36E−09

B. 485G10

The mouse antibody 485G10 variable region genes were employed to create a humanized MAb. In the first step of this process, the amino acid sequences of the VH and VK of 485G10 were compared against the available database of human Ig gene sequences to identify the overall best-matching human germline Ig gene sequences. For the heavy chain, the closest human match was the IGHV1-2*05 gene. For the light chain, the best human match was the IGKV1-16*01 gene.

Humanized variable domain sequences were then designed where the CDR1 (SEQ ID NO:92), 2 (SEQ ID NO:93), and 3 (SEQ ID NO:95) sequences of the 485G10 heavy chain were grafted onto framework sequences of the IGHV1-2*05 gene and the CDR1 (SEQ ID NO:96), 2 (SEQ ID NO:C5) and 3 (SEQ ID NO:98) of the 485G10 light chain were grafted onto framework sequences of the IGKV1-16*01 gene. A 3D model was then generated to determine if there were any framework positions where replacing the mouse amino acid to the human amino acid could affect binding and/or CDR conformation. In the case of the heavy chain, V20, A24, R38, M48, V68, M70, R72, M81, A97 (Kabat numbering) in human framework was identified and subjected to back-mutations to their moue counterpart amino acid i.e.: V20L, A24G, R38K, M48I, V68A, M70I, R72A, M81L, A97G. In the case of the light chain, A13, I21, F36, S46, L78, V104 (Kabat numbering) in human framework was identified and subjected to back-mutation to their moue counterpart amino acid i.e.: A13T, I21V, F36Y, S46P, L78V, V104L. At the meantime, G56 A mutation was employed to remove the PTM.

TABLE 9 485G10 sequences and CDRs Anti- body chain  SEQ or ID domain Sequences (CDR underlined and bold) NO:  485G10- EVQLQQSGAELVKPGASVKLSCTGSGFNIK 73 VH DYYIH WVKQRTEQGLEWIG RIDPEDGETKY APKFQG KATITADTSSNTAYLQLSSLTSED TVVYYCGR YHGYWALDY WGQGTSVTVSS 485G10- DIVMTQSQKFMSTSVGDRVSVTC KTSQNV 74 VL GTNVA WYQQKPGQSPKPLIY STSYRYS GVP DRFTGSGSGTDFTLIISNVQSEDLAEYFC HQYFSYPYT FGGGTLLEIK CDRH1 DYYIH 92 CDRH2 RIDPEDGETKYAPKFQG 93 CDRH2 RIDPED A ETKYAPKFQG 94 (modi- fied) CDRH3 YHGYWALDY 95 CDRL1 KTSQNVGTNVA 96 CDRL2 STSYRYS 97 CDRL3 HQYFSYPYT 98

The humanized sequences are listed in Table 10: 485G10-VH0, 485G10-VH1, 485G10-VH2, 485G10-VH3, 485G10-VL1, 485G10-VL2, 485G10-VL3, and 485G10-VL4.

TABLE 10 Humanized sequences Anti- SEQ body Sequences (CDR italic and underlined; ID chain back mutations bold) NO: 485G10- QVQLVQSGAEVKKPGASVKVSCKASGFNIK DYY I H WVRQAPGQGLEWMG R  99 VH0 IDPED

ETKYAPKFQG RVTMTRDTSISTAYMELSRLRSDDTVVYYCARYH GYWALDYWGQGTLVTVSS 485G10- QVQLVQSGAEVKKPGASVKVSCKASGFNIK DYY I H WVRQAPGQGLEWMG R 100 VH1 IDPED

ETKYAPKFQG RVTMTADTSISTAYMELSRLRSDDTVVYYCARYH GYWALDYWGQGTLVTVSS 485G10- QVQLVQSGAEVKKPGASVKLSCKASGFNIK DYY I H WVKQAPGQGLEWIG R 101 VH2 IDPED

ETKYAPKFQG RVTMTADTSISTAYMELSRLRSDDTVVYYCGRYH GYWALDYWGQGTLVTVSS 485G10- QVQLVQSGAEVKKPGASVKLSCKGSGFNIK DYY I H WVKQAPGQGLEWIG R 102 VH3 IDPED

ETKYAPKFQG RATITADTSISTAYLELSRLRSDDTVVYYCGRYH GYWALDYWGQGTLVTVSS 485G10- DIQMTQSPSSLSASVGDRVTITC KTSQNVGTNVA WFQQKPGKAPKSLIY S 103 VL1 TSYRYS GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC HQYFSYPYT FGP GTKVDIK 485G10- DIQMTQSPSSLSTSVGDRVTITC KTSQNVGTNVA WYQQKPGKAPKPLIY S 104 VL2 TSYRYS GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC HQYFSYPYT FGP GTKVDIK 485G10- DIQMTQSPSSLSTSVGDRVTITC KTSQNVGTNVA WYQQKPGKAPKPLIY S 105 VL3 TSYRYS GVPSRFSGSGSGTDFTLTISSVQPEDFATYYC HQYFSYPYT FGP GTKLDIK 485G10- DIQMTQSPSSLSTSVGDRVTVTC KTSQNVGTNVA WYQQKPGKAPKPLIY S 106 VL4 TSYRYS GVPSRFSGSGSGTDFTLTISSVQPEDFATYYC HQYFSYPYT FGP GTKLDIK

All the 16 IgGs could be expressed in the HEK293 cell line. Express antibodies were performed for affinity ranking. Detailed data of affinity ranking were summarized in table 11.

TABLE 11 Affinity ranking of humanized antibodies. Antibody k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) VH1 + VL3 3.11E+05 1.01E−04 3.25E−10 VH1 + VL2 3.08E+05 2.01E−04 6.52E−10 VH1 + VL4 3.27E+05 2.16E−04 6.60E−10 VH2 + VL3 2.81E+05 2.38E−04 8.48E−10 VH3 + VL2 3.06E+05 2.64E−04 8.64E−10 VH3 + VL4 3.54E+05 2.71E−04 7.66E−10 VH3 + VL3 3.32E+05 2.79E−04 8.41E−10 VH2 + VL2 3.29E+05 2.98E−04 9.06E−10 VH2 + VL4 3.03E+05 3.00E−04 9.90E−10 VH0 + VL3 2.94E+05 3.16E−04 1.07E−09 VH0 + VL4 2.55E+05 3.18E−04 1.25E−09 VH0 + VL2 2.79E+05 4.39E−04 1.57E−09 VH1 + VL1 3.28E+05 1.03E−03 3.14E−09 VH0 + VL1 5.09E+05 4.75E−03 9.33E−09 VH2 + VL1 3.23E+05 6.63E−03 2.05E−08 VH3 + VL1 9.71E+05 1.85E−02 1.91E−08

Based on the affinity ranking results, 4 IgGs (VH1+VL2, VH1+VL4, VH1+VL3, VH2+VL3) were expressed and purified. The purified antibodies were further selected for affinity measurement under different concentrations. Detailed data were summarized in Table 12.

TABLE 12 Affinity of selected humanized antibodies. Antibody ka (1/Ms) kd (1/s) KD (M) 485G10-H1L2 2.07E+05 3.21E−04 1.55E−09 485G10-H1L4 1.96E+05 2.59E−04 1.32E−09 485G10-H1L3 1.87E+05 2.32E−04 1.24E−09 485G10-H2L3 1.86E+05 3.66E−04 1.96E−09

Example 5. Anit-IFNAR-1 Humanized Monoclonal Antibodies Inhibit the Biological Activity of Interferon α2b in IFN-Responsive Reporter Assay

To evaluate the IFNAR-1-blocking function of humanized antibodies, in vitro IFN-responsive reporter assay described in Example 3 was used. HEK-Blue™ IFNα/β cells were incubated with 400 U/ml IFNα2b in the presence of serial diluted anti-IFNAR-1 humanized monoclonal antibodies overnight prior to determination by using a spectrophotometer at 650 nM. As shown in FIG. 1, the 8G11H, and 485G10H antibodies efficiently blocked IFNαc2b-induced reporter gene expression. Their potency is comparable to that of the corresponding chimeric antibodies.

Example 6. Anit-IFNAR-1 Humanized Monoclonal Antibodies Inhibit the Biological Activity of Interferon α2b in Daudi Cell Proliferation

The cell line Daudi, derived from a human B-lymphoblast Burkitt's lymphoma, expresses high levels of IFNAR, and the growth of these cells is inhibited by type I interferons. To measure the functional blocking ability of humanized anti-IFNAR-1 antibodies, Daudi cells were cultured with interferon oc2b in the presence or absence of a serial diluted anti-IFNAR-1 humanized antibodies. The cell proliferation was measured by Cell Counting Kit-8 (CCK8, DOJINDO Laboratories). As described in FIG. 2, the 8G11H and 485G10H antibodies dose-dependently reverse IFNαc2b-mediated inhibition of Daudi cell proliferation. Their potency is comparable to that of the corresponding chimeric antibodies.

Example 7. Anti-IFNAR-1 Human Monoclonal Antibodies Inhibit the Biological Activity of Multiple Type I IFNs

To assess the ability of humanized anti-IFNAR-1 antibodies to inhibit the biological activity of multiple type I IFNs, distinct IFN alpha subtypes were tested in the IFN-responsive reporter assay. HEK-Blue™ IFN-α/β cells were incubated with one of the following IFN alpha subtypes: 1, 2a, 4, 5, 6, 7, 8, 10, 14, 16, 17 and 21 in the presence of serial dilutions of the tested antibodies or an isotype control. The reporter signal was determined as described in Example 3. As shown in Table 13, the 8G11H and 485G10H antibodies can efficiently inhibit the cell signal elicited by multiple type I IFNs. Their EC₅₀ is in the pM level.

TABLE 13 Reporter assay of multiple Type I IFNs EC₅₀ (nM) Clone ID 8G11H 485G10H IFNα 1 0.057 0.051 IFNα 2a 0.052 0.048 IFNα 4 0.055 0.054 IFNα 5 0.087 0.098 IFNα 6 0.090 0.072 IFNα 7 0.039 0.047 IFNα 8 0.604 0.490 IFNα 10 0.402 0.550 IFNα 14 0.215 0.153 IFNα 16 0.061 0.079 IFNα 17 0.035 0.035 IFNα 21 0.079 0.065

Example 8. Anti-IFNAR-1 Human Monoclonal Antibodies Inhibit Type I IFN Mediated Anti-Viral Function

Type I IFNs were firstly identified by their unique anti-viral function. To evaluate the blocking effects of the anti-IFNAR-1 antibodies on type I IFN-mediated anti-viral function, an IFNα2b-based anti-viral assay was established. Briefly, cell line Huh7 was engineered to contain the full-length HCV genotype 1b replicon (Con1b) which was linked to a firefly luciferase reporter gene. The abundance of reporter gene closely correlated with replication levels of HCV replicon. The activity of anti-IFNAR-1 antibodies in blocking IFNα2b induced anti-viral function can be determined by the restoration of reporter gene levels in IFNαc2b-treated Huh7-Con1b cells.

Huh7-Con1b cells were cultured with 400 U/ml IFNα2b in the presence or absence of serial diluted anti-IFNAR-1 humanized monoclonal antibodies for 48 hours. The expression of firefly luciferase reporter gene was measured by addition of Britelite plus reagent and further determined by using a spectrophotometer. As shown in Table 14, anti-IFNAR-1 humanized monoclonal antibodies 8G11H and 485G10H efficiently inhibit IFNαc2b-induced anti-viral function, their EC50 is comparable to that of the corresponding chimeric antibodies.

TABLE 14 IFNα2b-mediated anti-viral assay Clone ID EC₅₀ (nM) 8G11-chimeric  7.733 8G11H  8.067 485G10-chimeric 16.267 485G10H 13.867

Example 9. Inhibition of Type I IFN-Induced IP-10 Secretion by Anti-IFNAR-1 Humanized Monoclonal Antibodies

Upon type I IFNs stimulation, normal peripheral blood mononuclear cells (PBMCs) express a serial of IFN-response genes including IP-10. The activity of anti-IFNAR-1 antibodies was tested for inhibition of IFNαc2b-induced secretion of IP-10 by normal PBMCs.

PBMCs were incubated with 400 U/ml IFNα2b in the presence or absence of anti-IFNAR-1 humanized monoclonal antibodies for 48 hours. Supernatants were collected and analyzed for IP-10 concentration by using a quantitative LANCE kit (Cisbio) according to manufacturer recommendations. As shown in FIG. 3, anti-IFNAR-1 humanized monoclonal antibodies 8G11H and 485G10H dose-dependently inhibit recombinant IFNαc2b-induced secretion of IP-10 by normal PBMC culture.

Example 10. Inhibition of Type I IFN-Induced Dendritic Cell Development by Anti-IFNAR-1 Humanized Monoclonal Antibodies

It is well known that type I IFNs induce the development and maturation of dendritic cells, as defined by the expression of specific cell surface markers such as CD38, CD80 and CD86 et al, and the capability to stimulate naïve allogeneic CD4⁺ T cell proliferation (mixed lymphocyte reaction, MLR). To evaluate the function of anti-IFNAR-1 antibodies in blocking type I IFN signaling on dendritic cells differentiation, IFNα2b-mediated dendritic cells differentiation assay was established. Monocytes isolated from human PBMCs were cultured with 20 ng/ml GMCSF and 400 U/ml IFNα2b in the presence or absence of anti-IFNAR-1 humanized monoclonal antibodies for 72 hours. Monocyte-derived dendritic cells were collected and further cultured with human naïve allogeneic CD4⁺ T cells at a ratio of 1:5 for 5 days. The cytokine IFN-γ, reflecting the proliferation status of CD4⁺ T cells, in the culture supernatants were analyzed by ELISA assay.

As shown in FIG. 4, the addition of anti-IFNAR-1 humanized monoclonal antibodies, 8G11H or 485G10H, into the differentiation systems results in significant reduction of cell surface markers CD38 and CD86 expression, as well as obvious impaired responses in MLR as demonstrated by decreased production of IFN-γ by CD4+ T cells (FIG. 5). The results demonstrated that anti-IFNAR-1 humanized monoclonal antibodies, 8G11H and 485G10H, can efficiently block IFNα2b signaling on dendritic cells development.

Example 11. Inhibition of SLE Plasma Mediated Dendritic Cell Development by Anti-IFNAR-1 Humanized Monoclonal Antibodies

The capacity of SLE patients' plasma to induce dendritic cell development correlates with disease activity and depends on the actions of IFNα. In this example, the purified human anti-IFNAR-1 antibodies, 8G11H and 485G10H, were tested for inhibition of SLE plasma-induced dendritic cell development, as assessed by the impaired capability of antibody-treated dendritic cells to stimulate naïve allogeneic CD4⁺ T cell proliferation (MLR).

Monocytes isolated from human PBMCs were cultured in media containing 25% SLE patient plasma in the presence or absence of anti-IFNAR-1 antibodies (15 μg/ml) for three to five days. The differentiated cells were then collected and co-cultured with human naïve allogeneic CD4⁺ T cells at a ratio of 1:5 for five days. The cytokine IFN-γ, reflecting the proliferation status of CD4⁺ T cells, in the culture supernatants were analyzed by ELISA assay. As shown in FIG. 6, anti-IFNAR-1 humanized monoclonal antibodies 8G11H and 485G10H significantly inhibit the IFNα-dependent dendritic cell development, as demonstrated by impaired capability of differentiated cells to stimulate MLR with marked reduction of the cytokine IFN-γ production by CD4⁺ T cells.

Example 12. Bispecific Antibody to Target BAFF and IFNAR-1

This example tested whether certain formats of anti-BAFF/anti-IFNAR1 bispecific antibodies can retain the binding affinities, and inhibitive activities, to both antigens.

The bispecific monoclonal antibody was generated with Belimumab (anti-BAFF) and 8G11 chimeric antibody. FIG. 7 depicts a schematic of designed four formats for the anti-IFNAR/BAFF bispecific antibody (Bi-BFINR). The binding properties of Bi-BFINR to human IFNAR-1 protein and human BAFF protein were detected respectively by ELISA assay. As shown in FIG. 8, the format 1 of Bi-BFINF exhibited similar activity as 8G11 antibody in binding to IFNAR-1 and comparable activity to Belimumab in binding to BAFF. Furthermore, cell-based assay was performed to characterize the biological function of Bi-BFINF. For anti-IFNAR-1 arm, IFNα2b-based reporter assay was applied. As shown in FIG. 9A, Bi-BFINF antibody with format 1 has the comparable activity to chimeric 8G11 in blocking IFNα2b signaling. For anti-BAFF arm, BAFF-induced B cell proliferation assay was performed. B cells isolated from Tonsil were cultured with 2 μg/ml recombinant BAFF in the presence or absence of Bi-BFINF for 72 hours. Cell-title glo was added to the cultures to determine B cell numbers. As shown in FIG. 9B, Bi-BFINF antibody with format 1 exhibits better activity in blockade of BAFF-induced B cell proliferation.

Example 13. Identification of Critical Amino Acids of hIFNAR-1 for 8G11 Binding

For epitope-mapping for the 8G11 antibody, a mutation library (alanine scan) of hIFNAR-1(1aa-409aa) was created. Binding of 8G11 Fab to each mutant clone in the alanine scanning library was determined, in duplicate, by high-throughput flow cytometry. For each point, background fluorescence was subtracted from the raw data, which were then normalized to Fab reactivity with WT target protein. For each mutant clone, the mean binding value was plotted as a function of expression (represented by control reactivity). 85288 Mab (R&D) and Anifrolumab were used as control antibody. To identify preliminary primary critical clones a threshold of >70% WT binding to control MAb or 8G11 Fab and <30% WT binding to test 8G11 Fab was applied.

Screening Results of the mutations are listed in Table 15. The clone H273A that did not meet the set thresholds but whose decreased binding activity and proximity to critical residues suggested that the mutated residue may be part of the antibody epitope. Critical residues whose mutation gave the lowest reactivities with specific antibodies are highlighted in bold and underlined. Validated critical residues represent amino acids whose side chains make the highest energetic contributions to the antibody-epitope interaction. Therefore, the highlighted (bold and underlined) residues K276, K278 are likely the major energetic contributors to binding. Results were showed in Table 16.

TABLE 15 Identification of critical residues for 8G11 Fab binding. Binding Reactivity (% WT) 8G11 85288 Mutation Fab Mab Anifrolumab Mab H273A 31.2 95.5 88.1 L274A 22.7 115.1 105.6 Y275A 19.1 86.8 145.5 K276A 1.5 104.4 99.4 K278A 3.9 101.2 105.1

TABLE 16 Important residues for binding of Fab to the hIFNAR-1 protein. Antibody Name Residues 8G11 H273, L274, Y275, K276, K278

Competition assays were used to test whether the antibodies 4D8, 8G11, 4B12, 30C8, 30B5, 34H8 and Anifrolumab competed with one another. The results showed that 4D8, 8G11, 4B12, 30C8, 30B5, and 34H8 competed with one another but none competed with Anifrolumab for binding to IFNAR-1. These data show that the newly identified antibodies target the same epitope on IFNAR-1 which is different from that for Anifrolumab.

Example 14. Pharmacokinetics of Humanized Anti-IFNAR1 Antibodies in Cynomolgus Monkeys

A preliminary pharmacokinetics (PK) study was conducted in cynomolgus monkeys at a dose of 10 mg/kg of 8G11-H2L1 and 485G10-H1L3. Serum samples were collected relative to antibody injection at −0 (predose), 5 Min, 30 Min, 1 h, 2h, 4h, 8h, 24 hr (1 day), 48 h (2 days), 72 hr (3 days), 96 hr (4 days), 120 hr (5 days), 168 hr (7 days), 240 hr (10 days), 36 hr (14 days), 504 hr (21 days), 672 hr (28 days) and 840 hr (35 days). The levels of anti-IFNAR1 mAbs were measured by a generic ELISA method using recombinant IFNAR1 protein ECD as the capture antigen. PK parameters were calculated based on statistical moment theory by WinNonlin 6.3 software. Results are shown in Table 17.

Time-concentration profiles indicated that the PK of 8G11-H2L1 and 485G10-H1L3 were more in line with what one would expect for a typical IgG (FIGS. 10A and 10B),

TABLE 17 8G11-H2L1 and 485G10-H1L3 PK parameters in cynomolgus monkeys i.v. 10 mg/kg 485G10-H1L3 8G11-H2L1 HL_Lambda_z h 41.9 71.37 T_(max) h 0.08 0.08 C_(max) μg/mL 299.05 241.32 AUC_(last) h * μg/mL 12942.47 15450.93 Vz_F_obs mL/kg 46.4 65.6 Cl_F_obs mL/h/kg 0.77 0.64 MRT_(last) h 62.43 99.49

Example 15. Pharmacodynamics of Humanized Anti-IFNAR1 Antibodies in Cynomolgus Monkeys

A pharmacodynamic (PD) model was to used study the ability of the anti-IFNAR1 antibodies to inhibit interferon activity in vivo. Cynomolgus monkeys were treated with i.v. infusion of 10 mg/kg 8G11-H2L1 and 485G10-H1L3 or vehicle control followed by i.m. dose of human IFN-α2b (3*10E6U/Kg). After treatment and IFN-α2b injection, blood was collected at pre-dose, 24, 72 and 168 h after treatment for PD marker measurement. The expression of CD11C, CD38, CD86, MHC Class I, MHC Class II and IFN-alpha R1 was detected by FACS in total PBMC. As shown in FIG. 11A, 8G11-H2L1 and 485G10-H1L3 could significantly decrease the HLA-DR expression of CD14+ cell at 24 h after treatment. Meanwhile, 8G11-H2L1 and 485G10-H1L3 were also able to suppress the IFN-alpha R1 expression of CD14+ cell both at 24 h and 72 h after treatment.

The serum levels of monkey neopterin and beta-2-microglobulin were detected by ELISA performed according to the manufacturer's instruction. The level of CRP in peripheral blood was measured by blood biochemistry. As shown in FIG. 11B, Neopterin, Beta-2 Microglobulin and CRP in vehicle group were increased rapidly within 24 h. Compared with vehicle control, 8G11-H2L1 and 485G10-H1L3 could suppress the neopterin and beta-2 Microglobulin significantly at 24 h and 72 h after dosing. Also, 8G11-H2L1 and 485G10-H1L3 were able to decrease the CRP significantly at 24 h after dosing.

The expression levels of type I IFN-induced gene signatures in peripheral blood mononuclear cells were detected by real-time PCR. As shown in FIG. 11C, the mRNA levels of ISG15, HERC5, IFI27 and IFIT3 were increased rapidly within 24 h in vehicle group. Compared with vehicle control, 8G11-H2L1 and 485G10-H1L3 significantly blocked the induction effects of type I IFN on these genes.

The present disclosure is not to be limited in scope by the specific embodiments described which are intended as single illustrations of individual aspects of the disclosure, and any compositions or methods which are functionally equivalent are within the scope of this disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the methods and compositions of the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference 

What is claimed is:
 1. An antibody or fragment thereof having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein, wherein the antibody or fragment thereof comprises a heavy chain variable region comprising heavy chain complementarity determining regions HCDR1, HCDR2, and HCDR3, and a light chain variable region comprising light chain complementarity determining regions LCDR1, LCDR2, and LCDR3, wherein the HCDR1 comprises the amino acid sequence of DYYIH (SEQ ID NO: 92), the HCDR2 comprises the amino acid sequence of RIDPEDGETKYAPKFQG (SEQ ID NO: 93) or RIDPEDAETKYAPKFQG (SEQ ID NO:94), the HCDR3 comprises the amino acid sequence of YHGYWALDY (SEQ ID NO: 95), the LCDR1 comprises the amino acid sequence of KTSQNVGTNVA (SEQ ID NO: 96), the LCDR2 comprises the amino acid sequence of STSYRYS (SEQ ID NO: 97), and the LCDR3 comprises the amino acid sequence of HQYFSYPYT (SEQ ID NO: 98).
 2. The antibody or fragment thereof of claim 1, wherein the antibody is a chimeric antibody or a humanized antibody.
 3. The antibody or fragment thereof of claim 1, which is humanized and wherein the heavy chain variable region comprises one or more back mutations selected from the group consisting of 20L, 24G, 38K, 48I, 68A, 70I, 72A, 81L, and 97G, according to Kabat numbering, and combinations thereof.
 4. The antibody or fragment thereof of claim 1, which is humanized and wherein the light chain variable region comprises one or more back mutations selected from the group consisting of 13T, 21V, 36Y, 46P, 78V, and 104L, according to Kabat numbering, and combinations thereof.
 5. The antibody or fragment thereof of claim 1, wherein the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 73, and 99-102.
 6. The antibody or fragment thereof of claim 1, wherein the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 74, and 103-106.
 7. The antibody or fragment thereof of claim 1, wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 100 and the light chain variable region comprises the amino acid sequence of SEQ ID NO:
 105. 8. A bifunctional molecule, comprising a first antigen-binding portion having specificity to a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein and a second portion having specificity to a second protein, wherein the first antigen-binding portion comprises an antibody fragment of claim
 1. 9. The bifunctional molecule of claim 8, wherein the second portion comprises peptide edratide (hCDR1) or TACI-Ig.
 10. The bifunctional molecule of claim 8, wherein the second portion is an antigen-binding fragment having specificity to a protein selected from the group consisting of BAFF, CD20, CD22, CTLA4, IL6, CXCL13 and C5.
 11. One or more polynucleotide encoding the antibody or fragment thereof of claim
 1. 12. A method of suppressing an immune response or treating an autoimmune disease or disorder in a patient in need thereof, comprising administering to the patient the antibody or fragment thereof of claim
 1. 13. The method of claim 12, for treating an autoimmune disease or disorder.
 14. The method of claim 13, wherein the autoimmune disease or disorder is selected from the group consisting of type 1 diabetes, rheumatoid arthritis (RA), psoriasis/psoriatic arthritis, multiple sclerosis, systemic lupus erythematosus (lupus), inflammatory bowel disease, Addison's disease, Graves' disease, Sjögren's syndrome, Hashimoto's thyroiditis, myasthenia gravis, vasculitis, pernicious anemia, and celiac disease.
 15. A method of detecting expression of a human interferon alpha and beta receptor subunit 1 (IFNAR1) protein in a sample, comprising contacting the sample with the antibody or fragment thereof of claim 1, and detecting the binding which indicates expression of IFNAR1 in the sample. 